Timeline of Arizona history

This timeline is a chronology of significant events in the history of the U.S. State of Arizona and the historical area now occupied by the state.

2000s 1900s Statehood 1800s Territory 1700s 1600s 1500s Before 1492

2020s

Year	Date	Event
2020	November 3	In the 2020 General Election, Arizona voters elect 11 U.S. Presidential Electors for Joe Biden, elect Mark Kelly as new U.S. Senator, and re-elect all nine incumbent U.S. Representatives. Republicans retain control of the Arizona State Legislature.
2020	April 1	The 2020 United States Census enumerates the population of the State of Arizona, estimated to be about 7,388,000. Arizona may gain a 10th Congressional seat.

2010s

Year	Date	Event
2019	January 3	Kyrsten Sinema and Martha McSally assume office as the U.S. Senators representing the State of Arizona.
2015	January 5	Doug Ducey assumes office as the Governor of the State of Arizona.
2013	June 30	19 members of the Prescott Fire Department were killed fighting the Yarnell Hill Fire.[1]
2010	April 1	The 2010 United States Census enumerates the population of the State of Arizona, later determined to be 6,392,017, an increase of 24.6% since the 2000 United States Census. Arizona becomes the 16th most populous of the 50 U.S. states and gains a 9th Congressional District.

2000s

Year	Date	Event
2009	January 21	Arizona Secretary of State Jan Brewer assumes office as the Governor of the State of Arizona upon the resignation of Governor Napolitano.
2008	November 4	Arizona U.S. Senator John McCain losses the 2008 United States presidential election to Illinois U.S. Senator Barack Obama.
2003	March 6	Janet Napolitano assumes office as the Governor of the State of Arizona.
2001	January 17	U.S. President Bill Clinton issues an executive order creating Sonoran Desert National Monument.[2]
2000	November 9	U.S. President Bill Clinton issues an executive order creating Vermilion Cliffs National Monument.[2]
	June 9	U.S. President Bill Clinton issues an executive order creating Ironwood Forest National Monument.[2]
	January 11	U.S. President Bill Clinton issues an executive order creating Agua Fria National Monument and Grand Canyon–Parashant National Monument.[2]
	April 1	The 2000 United States Census enumerates the population of the State of Arizona, later determined to be 6,392,017, an increase of 40.0% since the 1990 United States Census. Arizona becomes the 20th most populous of the 50 U.S. states and gains a 7th Congressional District and an 8th Congressional District.

1990s

Year	Date	Event
1997	September 5	Arizona Secretary of State Jane Dee Hull assumes office as the Governor of the State of Arizona upon the resignation of Governor Symington.
1994	August 6	U.S. President Bill Clinton signs An Act to establish the Saguaro National Park in the State of Arizona, and for other purposes, creating Saguaro National Park from Saguaro National Monument.[2][3]
1991	March 6	Fife Symington assumes office as the Governor of the State of Arizona.
1990	August 6	U.S. President George H. W. Bush signs An Act to establish the Tumacacori National Historical Park in the State of Arizona, creating Tumacacori National Historical Park from Tumacacori National Monument.[2][3]
1990	April 1	The 1990 United States Census enumerates the population of the State of Arizona, later determined to be 3,665,228, an increase of 34.8% since the 1980 United States Census. Arizona becomes the 24th most populous of the 50 U.S. states and gains a 6th Congressional District.

1980s

Year	Date	Event
1988	April 4	Arizona Secretary of State Rose Mofford assumes office as the Governor of the State of Arizona upon the impeachment and removal from office of Governor Mecham.
1987	January 5	Evan Mecham assumes office as the Governor of the State of Arizona.
1987	January 3	John McCain assumes office as the junior U.S. senator representing the State of Arizona.
1983	January 1	The State of Arizona creates La Paz County from a portion of Yuma County.[4]
1980	April 1	The 1980 United States Census enumerates the population of the State of Arizona, later determined to be 2,718,215, an increase of 55.7% since the 1970 United States Census. Arizona becomes the 29th most populous of the 50 U.S. states and gains a 5th Congressional District.

1970s

Year	Date	Event
1978	March 4	Arizona Attorney General Bruce Babbitt assumes office as the Governor of the State of Arizona upon the death of Governor Bolin.
1977	October 20	Arizona Secretary of State Wesley Bolin assumes office as the Governor of the State of Arizona upon the resignation of Governor Castro.
1975	January 6	Raúl Héctor Castro assumes office as the Governor of the State of Arizona.
1975	January 3	U.S. President Gerald Ford signs An Act to further protect the outstanding scenic, natural, and scientific values of the Grand Canyon by enlarging the Grand Canyon National Park in the State of Arizona, and for other purposes, annexing Grand Canyon National Monument and Marble Canyon National Monument to Grand Canyon National Park.[2][3]
1972	October 21	U.S. President Richard Nixon signs An Act to provide for the establishment of the Hohokam Pima National Monument in the vicinity of the Snaketown archeological site, Arizona, and for other purposes.[2][3]
1970	April 1	The 1970 United States Census enumerates the population of the State of Arizona, later determined to be 1,745,944, an increase of 34.1% since the 1960 United States Census. Arizona becomes the 33rd most populous of the 50 U.S. states and gains a 4th Congressional District.

1960s

Year	Date	Event
1969	July 25	U.S. President Lyndon B. Johnson issues an executive order creating Marble Canyon National Monument.[2][3]
1967	January 2	Jack Williams assumes office as the Governor of the State of Arizona.
1965	August 28	U.S. President Lyndon B. Johnson signs An Act to authorize the establishment of the Hubbell Trading Post National Historic Site, in the State of Arizona, and for other purposes.[3]
1965	January 4	Samuel Pearson Goddard Jr. assumes office as the Governor of the State of Arizona.
1964	November 3	Senior Arizona U.S. Senator Barry Goldwater losses the 1964 United States presidential election to U.S. President Lyndon B. Johnson.
1964	July 25	U.S. President Lyndon B. Johnson signs An Act to authorize the establishment of the Fort Bowie National Historic Site in the State of Arizona, and for other purposes.[3]
1960	April 1	The 1960 United States Census enumerates the population of the State of Arizona, later determined to be 1,302,161, an increase of 73.7% since the 1950 United States Census. Arizona becomes the 35th most populous of the 50 U.S. states and gains another Congressional seat to form the 1st, 2nd, 3rd Congressional Districts.

1950s

Year	Date	Event
1959	January 5	Paul Fannin assumes office as the Governor of the State of Arizona.
1958	October 23	U.S. President Dwight D. Eisenhower signs An Act to authorize the establishment of the Petrified Forest National Park in the State of Arizona, and for other purposes, creating Petrified Forest National Park from Petrified Forest National Monument.[2][3]
1955	January 3	Ernest McFarland assumes office as the Governor of the State of Arizona.
1953	October 23	U.S. President Dwight D. Eisenhower signs Public Land Order 924 abolishing Crook National Forest and transferring its land to Coronado National Forest, Gila National Forest, and Tonto National Forest.[5]
1953	January 3	Barry Goldwater assumes office as the junior U.S. senator representing the State of Arizona.
1952	October 23	U.S. President Harry S. Truman signs An Act To amend the Act entitled "An Act to provide for the establishment of the Coronado International Memorial, in the State of Arizona", approved August 18, 1941, creating Coronado National Memorial.[3]
1951	January 1	John Howard Pyle assumes office as the Governor of the State of Arizona.
1950	April 1	The 1950 United States Census enumerates the population of the State of Arizona, later determined to be 749,587, an increase of 50.1% since the 1940 United States Census. Arizona becomes the 37th most populous of the 48 U.S. states.

1940s

Year	Date	Event
1948	May 25	Arizona Secretary of State Dan Edward Garvey assumes office as the Governor of the State of Arizona upon the death of Governor Osborn.
1941	January 2	Sidney Preston Osborn assumes office as the Governor of the State of Arizona.
1940	April 1	The 1940 United States Census enumerates the population of the State of Arizona, later determined to be 499,261, an increase of 14.6% since the 1930 United States Census. Arizona remains the 43rd most populous of the 48 U.S. states but gains a 2nd Congressional seat.

1930s

Year	Date	Event
1939	July 25	U.S. President Franklin D. Roosevelt issues an executive order creating Tuzigoot National Monument.[2][3]
1939	January 2	Robert Taylor Jones assumes office as the Governor of the State of Arizona.
1937	April 13	U.S. President Franklin D. Roosevelt issues an executive order creating Organ Pipe Cactus National Monument.[2][3]
1937	January 4	Rawghlie Clement Stanford assumes office as the Governor of the State of Arizona.
1934	October 22	U.S. President Franklin D. Roosevelt issues Executive Order 6882 merging Tusayan National Forest into Prescott National Forest.[2][3]
1933	March 1	U.S. President Herbert Hoover issues an executive order creating Saguaro National Monument.[2][3]
1933	January 2	Benjamin Baker Moeur assumes office as the Governor of the State of Arizona.
1932	December 22	U.S. President Herbert Hoover issues an executive order creating a new Grand Canyon National Monument.[2][3]
1931	December 22	U.S. President Herbert Hoover issues an executive order creating Canyon de Chelly National Monument.[2][3]
1931	January 5	George W. P. Hunt assumes office as the Governor of the State of Arizona.
1930	May 26	U.S. President Herbert Hoover issues an executive order creating Sunset Crater National Monument.[2][3]
	April 7	U.S. President Herbert Hoover signs An Act to abolish the Papago Saguaro National Monument, Arizona, to provide for the disposition of certain lands therein for park and recreational uses, and for other purposes, transferring Papago Saguaro National Monument to the State of Arizona.[2][3]
	April 1	The 1930 United States Census enumerates the population of the State of Arizona, later determined to be 435,573, an increase of 30.3% since the 1920 United States Census. Arizona becomes the 43rd most populous of the 48 U.S. states.

1920s

Year	Date	Event
1929	January 7	John Calhoun Phillips assumes office as the Governor of the State of Arizona.
1924	December 9	U.S. President Calvin Coolidge issues an executive order creating Wupatki National Monument.[2][3]
	June 2	U.S. President Calvin Coolidge signs An Act To authorize the Secretary of the Interior to issue certificates of citizenship to Indians, also known as the Indian Citizenship Act of 1924, finally granting full United States Citizenship to all Native Americans born in the United States.[6]
	April 18	U.S. President Calvin Coolidge issues an executive order creating Chiricahua National Monument.[2][3]
1923	May 31	U.S. President Warren G. Harding issues an executive order creating Pipe Spring National Monument.[2][3]
1923	January 1	George W. P. Hunt assumes office as the Governor of the State of Arizona.
1920	April 1	The 1920 United States Census enumerates the population of the State of Arizona, later determined to be 334,162, an increase of 63.5% since the 1910 United States Census. Arizona becomes the 45th most populous of the 48 U.S. states

1910s

Year	Date	Event
1919	February 26	U.S. President Woodrow Wilson signs An Act to establish the Grand Canyon National Park in the State of Arizona, creating Grand Canyon National Park from Grand Canyon National Monument.[3]
1919	January 6	Thomas Edward Campbell assumes office as the Governor of the State of Arizona.
1918	August 3	U.S. President Woodrow Wilson issues an executive order creating Casa Grande National Monument from the Casa Grande Ruin Reservation.[2][3]
1917	December 25	George W. P. Hunt resumes office as the Governor of the State of Arizona following a court decision.
	June 6	U.S. President Woodrow Wilson issues Executive Order 2630 merging Chiricahua National Forest into Coronado National Forest.[5]
	January 1	Thomas Edward Campbell assumes office as the Governor of the State of Arizona.
1916	August 25	U.S. President Woodrow Wilson signs An Act To establish a National Park Service, and for other purposes.[7]
1915	January 31	U.S. President Woodrow Wilson issues an executive order creating Walnut Canyon National Monument.[2][3]
1914	September 10	U.S. President Woodrow Wilson issues Executive Order 2045 merging Zuni National Forest into Manzano National Forest.[5]
1914	January 10	U.S. President Woodrow Wilson issues an executive order creating Papago Saguaro National Monument.[2]
1912	February 14	George W. P. Hunt assumes office as the first Governor of the State of Arizona.
1912	February 14	U.S. President William Howard Taft issues Proclamation 1180: Admitting Arizona to the Union.[8] The Territory of Arizona becomes the State of Arizona, the 48th U.S. state.
1911	June 28	U.S. President William Howard Taft issues Proclamation 1121 merging Garces National Forest into Coronado National Forest.[5]
1910	June 28	U.S. President William Howard Taft issues Proclamation 1049 creating Tusayan National Forest.[5]
	June 20	U.S. President William Howard Taft signs An Act to enable the people of New Mexico to form a constitution and state government and be admitted into the Union on an equal footing with the original States; and to enable the people of Arizona to form a constitution and state government and be admitted into the Union on an equal footing with the original States.[9]
	April 1	The 1910 United States Census enumerates the population of the Territory of Arizona, later determined to be 204,354, an increase of 66.2% since the 1900 United States Census. Arizona becomes the second most populous of the four U.S. territories.

1900s

Year	Date	Event
1909	September 15	U.S. President William Howard Taft issues a proclamation creating Navajo National Monument.[2][3]
	May 1	U.S. President William Howard Taft appoints Richard Elihu Sloan as the 17th (and last) Governor of the Territory of Arizona.
	March 10	The Territory of Arizona creates Greenlee County from a portion of Graham County.[4]
	March 2	U.S. President Theodore Roosevelt issues Proclamation 864 creating Zuni National Forest.[5]
1908	September 15	U.S. President Theodore Roosevelt issues a proclamation creating Tumacacori National Monument.[2][3]
	July 2	U.S. President Theodore Roosevelt issues Proclamation 909 creating Kaibab National Forest subsuming Grand Canyon National Forest.[5]
		U.S. President Theodore Roosevelt issues Proclamation 908 (1) creating Coronado National Forest subsuming Dragoon National Forest, Santa Catalina National Forest, and Santa Rita National Forest; and (2) creating Garces National Forest subsuming Baboquivari National Forest, Huachuca National Forest, and Tumacacori National Forest; and (3) merging Verde National Forest into Prescott National Forest.[5]
		U.S. President Theodore Roosevelt issues Proclamation 818 creating Coconino National Forest subsuming San Francisco Mountains National Forest.[5]
	July 1	U.S. President Theodore Roosevelt issues Proclamation 816 creating Crook National Forest subsuming Mount Graham National Forest.[5]
		U.S. President Theodore Roosevelt issues Proclamation 876 creating Apache National Forest.[5]
		U.S. President Theodore Roosevelt issues Proclamation 868 creating Sitgreaves National Forest.[5]
	January 13	U.S. President Theodore Roosevelt issues Procamation 795 merging Pinal Mountains National Forest into Tonto National Forest.[5]
	January 11	U.S. President Theodore Roosevelt issues a proclamation creating Grand Canyon National Monument.[2][3]
1907	December 30	U.S. President Theodore Roosevelt issues Proclamation 789 creating Verde National Forest.[5]
	December 19	U.S. President Theodore Roosevelt issues a proclamation creating Tonto National Monument.[2][3]
	May 25	U.S. President Theodore Roosevelt issues a proclamation creating Dragoon National Forest.[5]
1906	December 8	U.S. President Theodore Roosevelt issues proclamations creating Montezuma Castle National Monument and Petrified Forest National Monument, the first National Monuments in Arizona.[2][3]
	November 7	U.S. President Theodore Roosevelt issues a proclamation creating the Tumacacori Forest Reserve.[5]
	November 6	U.S. President Theodore Roosevelt issues a proclamation creating the Huachuca Forest Reserve.[5]
	November 5	U.S. President Theodore Roosevelt issues a proclamation creating the Baboquivari Forest Reserve.[5]
	August 8	U.S. President Theodore Roosevelt issues a proclamation changing the name of the Grand Cañon Forest Reserve to the Grand Canyon Forest Reserve.[5]
	June 8	U.S. President Theodore Roosevelt signs An Act For the preservation of American antiquities, also known as the Antiquities Act of 1906, giving the President of the United States the authority to create national monuments on federal lands to protect significant natural, cultural, or scientific features.[10]
1905	October 3	U.S. President Theodore Roosevelt issues a proclamation order creating the Tonto Forest Reserve.[5]
	March 20	U.S. President Theodore Roosevelt issues a proclamation creating the Pinal Mountains Forest Reserve.[5]
	March 7	U.S. President Theodore Roosevelt appoints Joseph Henry Kibbey as the 16th Governor of the Territory of Arizona.
1902	July 30	U.S. President Theodore Roosevelt issues Proclamation 33 creating the Chiricahua Forest Reserve.[5]
	July 22	U.S. President Theodore Roosevelt issues Proclamation 31 creating the Mount Graham Forest Reserve.[5]
	July 2	U.S. President Theodore Roosevelt issues Proclamation 27 creating the Santa Catalina Forest Reserve.[5]
	July 1	U.S. President Theodore Roosevelt appoints Alexander Oswald Brodie as the 15th Governor of the Territory of Arizona.
	April 11	U.S. President Theodore Roosevelt issues Proclamation 14 creating the Santa Rita Forest Reserve.[5]
1900	April 1	The 1900 United States Census enumerates the population of the Territory of Arizona, later determined to be 122,931, an increase of 39.3% since the 1890 United States Census. Arizona becomes the fourth most populous of the five U.S. territories.

1890s

Year	Date	Event
1899	March 15	The Territory of Arizona creates Santa Cruz County from portions of Cochise County and Pima County.[4]
1898	December 10	The United States of America and the Kingdom of Spain sign the Treaty of Paris of 1898 to end the Spanish–American War.
	August 17	U.S. President William McKinley issues Proclamation 19 creating the Black Mesa Forest Reserve.[5]
	August 17	U.S. President William McKinley issues Proclamation 18 creating the San Francisco Mountains Forest Reserve and the Black Mesa Forest Reserve.[5]
	August 12	The United States of America and the Kingdom of Spain sign a Protocol of Peace.
	August 1	U.S. President William McKinley appoints Oakes Murphy as the 14th Governor of the Territory of Arizona.
	May 10	U.S. President William McKinley issues Proclamation 9 creating the Prescott Forest Reserve.[5]
	April 23	The Kingdom of Spain declares war on the United States of America. The United States declares war on Spain two days later.
1897	July 29	U.S. President William McKinley appoints Myron H. McCord as the 13th Governor of the Territory of Arizona.
1896	April 18	U.S. President Grover Cleveland appoints Benjamin Joseph Franklin as the 12th Governor of the Territory of Arizona.
1895	March 21	The Territory of Arizona creates Navajo County from a portion of Apache County.[4]
1893	April 12	U.S. President Grover Cleveland appoints L.C. Hughes as the 11th Governor of the Territory of Arizona.
1893	February 20	U.S. President Benjamin Harrison issues Proclamation 45 creating the Grand Cañon Forest Reserve, the first National Forest in Arizona.[5]
1892	May 11	U.S. President Benjamin Harrison appoints Oakes Murphy as the tenth Governor of the Territory of Arizona.
1891	March 3	U.S. President Benjamin Harrison signs An act to repeal timber-culture laws, and for other purposes, also known as the Forest Reserve Act of 1891, giving the President of the United States the authority to create protected national forests on federal lands.[11]
	February 18	The Territory of Arizona creates Coconino County from a portion of Yavapai County.[4]
	January 21	U.S. President Benjamin Harrison appoints John N. Irwin as the ninth Governor of the Territory of Arizona.
1890	April 1	The 1890 United States Census enumerates the population of the Territory of Arizona, later determined to be 88,243, an increase of 218.2% since the 1880 United States Census. Arizona becomes the fifth most populous of the six U.S. territories.

1880s

Year	Date	Event
1889	April 8	U.S. President Benjamin Harrison appoints Lewis Wolfley as the eighth Governor of the Territory of Arizona.
1889	March 2	U.S. President Grover Cleveland issues an executive order creating the Casa Grande Ruin Reservation.[3]
1885	November 2	U.S. President Grover Cleveland appoints C. Meyer Zulick as the seventh Governor of the Territory of Arizona.
1882	March 8	U.S. President Chester A. Arthur appoints Frederick Augustus Tritle as the sixth Governor of the Territory of Arizona.
1881	March 10	The Territory of Arizona creates Graham County from portions of Apache County and Pima County.[4]
	February 8	The Territory of Arizona creates Gila County from portions of Maricopa County and Pinal County.[4]
	February 1	The Territory of Arizona creates Cochise County from a portion of Pima County.[4]
1880	April 1	The 1880 United States Census enumerates the population of the Territory of Arizona, later determined to be 40,440, an increase of 418.7% since the 1870 United States Census. Arizona becomes the fifth most populous of the eight U.S. territories.

1870s

Year	Date	Event
1879	February 24	The Territory of Arizona creates Apache County from a portion of Yavapai County.[4]
1878	October 6	U.S. President Rutherford B. Hayes appoints John C. Frémont as the fifth Governor of the Territory of Arizona.
1877	July 9	U.S. President Rutherford B. Hayes appoints John Philo Hoyt as the fourth Governor of the Territory of Arizona.
1875	February 1	The Territory of Arizona creates Pinal County from portions of Maricopa County and Pima County.[4]
1871	February 18	The Territory of Arizona abolishes Pah-Ute County and annexes the remainder of the county in the Territory of Arizona to Mohave County.[4]
1871	February 14	The Territory of Arizona creates Maricopa County from portions of Pima County and Yavapai County.[4]
1870	April 1	The 1870 United States Census enumerates the population of the Territory of Arizona, later determined to be 9,658. Arizona becomes the eighth most populous of the nine U.S. territories.

1860s

Year	Date	Event
1869	July 9	U.S. President Ulysses S. Grant appoints Anson P.K. Safford as the third Governor of the Territory of Arizona.
1867	January 18	The State of Nevada accepts the portion the Territory of Arizona lying west of the 37th meridian west from Washington and the River Colorado of the West. The boundaries of the Territory of Arizona are now the same as the future State of Arizona.
1866	July 9	U.S. President Andrew Johnson appoints Richard Cunningham McCormick as the second Governor of the Territory of Arizona.
1865	December 22	The Territory of Arizona creates Pah-Ute County from a portion of Mohave County.[4]
1865	May 9	U.S. President Andrew Johnson proclaims the end of the American Civil War.
1864	November 9	The Territory of Arizona creates four original counties: Mohave County, Pima County, Yavapai County, and Yuma County.[4]
1863
	December 29	U.S. President Abraham Lincoln appoints John Noble Goodwin as the first Governor of the Territory of Arizona.
	February 24	U.S. President Abraham Lincoln signs An Act to provide a temporary Government for the Territory of Arizona, and for other Purposes.[12] The act creates the Territory of Arizona from the portion of the Territory of New Mexico lying west of the 32nd meridian west from Washington (109°02′42.6″W). The Territory of Arizona includes all of the future State of Arizona plus the portion of the present-day State of Nevada lying south of the 37th parallel north.
1862	July 27	The United States Army establishes Fort Bowie near Apache Pass.
	July	Texas cavalry retreat to Texas
	June 19	U.S. President Abraham Lincoln signs An Act to secure Freedom to all Persons within the Territories of the United States, granting freedom to the slaves in all U.S. territories.
	April 15	California cavalry engage Texas cavalry in the Battle of Picacho Pass, the westernmost battle of the American Civil War.
	February 28	Texas cavalry occupy Tucson.
	February 24	Confederate President Jefferson Davis proclaims that the portion of the Territory of New Mexico lying south of the 34th parallel north is the Confederate Territory of Arizona.
	February	The California Column departs Fort Yuma and advances into the Territory of New Mexico.
1861	July 25	Texas cavalry under the command of Lieutenant Colonel John R. Baylor invades the Territory of New Mexico and occupies the town of Mesilla.
	April 12	The American Civil War begins with the Battle of Fort Sumter.
	March 4	Abraham Lincoln assumes office as the 16th President of the United States.
	February 28	U.S. President James Buchanan signs An Act to provide a temporary Government for the Territory of Colorado, creating the free Territory of Colorado. The Territory of Colorado annexes the portion of the Territory of New Mexico lying north of the 37th parallel north. The Territory of New Mexico now includes all of the future states of Arizona and New Mexico plus the portion of the present-day State of Nevada lying south of the 37th parallel north.
	February 8	The seven secessionist slave states create the Confederate States of America.
1860	November 6	Abraham Lincoln is elected President of the United States. Seven slave states will secede from the United States of America before February 8, 1861.
1860	April 1	The 1860 United States Census enumerates the population of the Territory of New Mexico, later determined to be 93,516, an increase of 51.9 since the 1850 United States Census. New Mexico becomes the second most populous of the seven U.S. territories.

1850s

Year	Date	Event
1858	September	The Overland Mail Company makes Tucson its 3rd division headquarters.
1857	August	The San Antonio–San Diego Mail Line reaches Tucson.
1854	June 8	The Gadsden Purchase goes into effect creating the current United States-Mexico border. The Territory of New Mexico now includes all of the future states of Arizona and New Mexico plus portions of the present-day states Nevada and Colorado.
1852	January 9	The Territory of New Mexico creates nine original counties: Bernalillo County, Doña Ana County, Rio Arriba County, San Miguel County, Santa Ana County, Santa Fe County, Socorro County, Taos County, and Valencia County. Doña Ana County and Socorro County extend into the future State of Arizona. Rio Arriba County, Santa Ana County, and Valencia County extend into the future states of Arizona and Nevada. Taos County extends into the future states of Arizona, Colorado, and Nevada[4]
1851	September 18	Colonel Edwin Vose Sumner establishes Fort Defiance, the first United States establishment in the future State of Arizona.
1851	April 5	The State of Deseret dissolves.
1850	September 9	The Territory of New Mexico and the Territory of Utah are established as part of the Compromise of 1850. U.S. President Millard Fillmore signs An Act proposing to the State of Texas the Establishment of her Northern and Western Boundaries, the Relinquishment by the said State of all Territory claimed by her exterior to said Boundaries, and of all her Claims upon the United States, and to establish a territorial Government for New Mexico. The Territory of New Mexico includes all of the future states of Arizona and New Mexico except the portion that shall be added by the Gadsden Purchase, plus portions of the present-day states of Colorado and Nevada.
	June 20	In a failed attempt to organize a slave State of New Mexico, a state constitution is adopted by a vote of 6,771 to 39 and Henry Connelly is elected governor. U.S. military and civilian governor John Munroe refuses to let those elected take office without the express approval of the United States Congress.
	April 1	The 1850 United States Census makes the first enumeration of the population of the future Territory of New Mexico, later determined to be 61,547.

1840s

Year	Date	Event
1849	March 12	The Mormon settlers of the Great Salt Lake Valley create the Provisional Government of the State of Deseret and elect Brigham Young as the first (and only) Governor. The proposed state includes the entire Great Basin and the entire drainage basin of the Colorado River within the United States. Although the proposed State of Deseret includes most of the future State of Arizona, it has no actual presence in the region.
1848	February 2	The United States and United Mexican States sign the Treaty of Guadalupe Hidalgo to end the Mexican–American War. Mexico relinquishes its northern territories. All land in the future State of Arizona north of the Mexican border becomes unorganized United States territory.
1846	September 22	The Mormon Battalion under the command of Lieutenant Colonel Philip St. George Cooke occupies Tucson, Sonora.
	September 22	Brigadier General Stephen W. Kearny appoints Charles Bent as the first U.S. civilian governor of New Mexico.
	August 22	Brigadier General Stephen W. Kearny assumes command as the first U.S. military governor of New Mexico.
	August 18	Troops under the command of General Stephen W. Kearny seize Santa Fe for the United States with little resistance.
	August 15	U.S. Army troops under the command of Brigadier General Stephen W. Kearny enter Las Vegas, New Mexico. General Kearny proclaims that all of New Mexico is now under United States rule.
	May 13	The United States declares war on the Mexican Republic.

1820s

Year	Date	Event
1821	August 24	Ferdinand VII of Spain signs the Treaty of Córdoba recognizing the independence of the Mexican Empire.

1810s

Year	Date	Event
1810	August 1	Mexican priest Miguel Gregorio Antonio Ignacio Hidalgo-Costilla y Gallaga Mandarte Villaseñor (Hidalgo) proclaims the independence of Mexico from the Napoleonic Kingdom of Spain in the village of Dolores.

1790s

Year	Date	Event

1780s

Year	Date	Event
1783	September 3	The Treaty of Paris is signed in Paris by representatives of King George III of Great Britain and representatives of the United States of America. The treaty affirms the independence of the United States and sets the Mississippi River as its western boundary.

1770s

Year	Date	Event
1776	July 29	A Spanish-Franciscan expedition led by Franciscan priests Francisco Atanasio Domínguez and Silvestre Vélez de Escalante sets out from La Villa Real de la Santa Fé de San Francisco de Asís (Santa Fe) in search of an overland route to the Presidio Reál de San Carlos de Monterey (Monterey). The expedition follows the 1765 route of Juan Rivera northwest across the Colorado Plateau. The expedition fails to reach Las Californias, but reaches the lower Paria River in the future State of Arizona before returning to Santa Fe.
1776	July 4	Representatives of the thirteen United States of America sign the Declaration of Independence from the Kingdom of Great Britain.

1690s

Year	Date	Event

1590s

Year	Date	Event
1598	July 12	Don Juan de Oñate y Salazar establishes the Virreinato de Nueva España colony of Santa Fe de Nuevo Méjico at the village of San Juan de los Caballeros adjacent to the Ohkay Owingeh Pueblo at the confluence of the Rio Grande and the Río Chama.

1540s

Year	Date	Event
1540	July 7	The military expedition led by Francisco Vásquez de Coronado, reaches the Zuni pueblo of Hawikuh. The Zuni resist but are driven off by the Spanish soldiers. Fray Marcos de Niza returns to Compostela in disgrace.
1540	February 23	Francisco Vásquez de Coronado, Governor of Nueva Galicia, departs Compostela, México commanding a Spanish military expedition of 400 soldiers, 1,300 to 2,000 Mexican Indian allies, four Franciscan friars including Marcos de Niza and Juan de Padilla, and several slaves.

1530s

Year	Date	Event
1539	September	Fray Marcos de Niza returns to San Miguel de Culiacán after a distant view of the Zuni pueblo of Hawikuh. His glowing reports of Hawikuh inspire the 1540-1542 expedition of Francisco Vásquez de Coronado.
1539	March	Mustafa Azemmouri (Estevanico) leaves San Miguel de Culiacán followed by Fray Marcos de Niza in search of the Seven Cities of Cibola. Mustafa Azemmouri becomes the first African and Marcos de Niza becomes the first European to visit the future State of Arizona. Mustafa Azemmouri is murdered at the Zuni pueblo of Hawikuh.
1536	July	The four survivors of the Narváez expedition of 1527 arrive in Mexico City. Reports of their travels inspire stories of the Seven Cities of Cibola.
1535		The four survivors of the Narváez expedition of 1527: Álvar Núñez Cabeza de Vaca, Andrés Dorantes de Carranza, Alonso del Castillo Maldonado, and Mustafa Azemmouri (slave name: Estevanico), may have traveled through the southern portion of the future State of Arizona.

1510s

Year	Date	Event
1513	September 29	Spanish conquistador Vasco Núñez de Balboa crosses the Isthmus of Panama and arrives on the shore of a sea that he names Mar del Sur (the South Sea, later named the Pacific Ocean). He claims the sea and all adjacent lands for the Queen of Castile. This includes all of the future State of Arizona.

1490s

Year	Date	Event
1493	May 5	Pope Alexander VI (born Roderic de Borja in Valencia) issues the papal bull Inter caetera which splits the non-Christian world into two halves. The eastern half goes to the King of Portugal for his exploration, conquest, conversion, and exploitation. The western half (including all of North America) goes to the Queen of Castile and the King of Aragon for their exploration, conquest, conversion, and exploitation. The indigenous peoples of the Americas have no idea that any of these people exist.
1492	October 12	Genoese seaman Cristòffa Cómbo (Christopher Columbus) leading an expedition for Queen Isabella I of Castile lands on the Lucayan island of Guanahani that he renames San Salvador. This begins the Spanish conquest of the Americas.

Before 1492

Era	Event
c. 12,000 BCE	During a centuries long period of warming, ice-age Paleoamericans from Beringia begin using the ice-free corridor along the Rocky Mountains to migrate throughout the Americas.