Grand station (CTA Logan Square branch)

Plans for Chicago to have a subway system to relieve the severe congestion of, if not replace, its elevated trackage dated back to the early 20th century, but the city lagged in building subways.[19] A plan developed for a subway to directly connect the west side with downtown;[20] a 1939 plan also introduced the idea of replacing the Metropolitan's main line and Garfield Park branch with a section of rapid transit operating through a proposed Congress superhighway (the eventual Interstate 290). These sections of transit would be connected, allowing for the area's rapid transit to be routed through downtown rather than adhere to a trunk-and-branch model.[21]

The subway's approval did not immediately imply the end of the old Logan Square branch; plans in 1939 included another proposed subway to connect the branch with the Ravenswood branch to the north and through-routing it with the Douglas Park branch to the south into a subway on Ashland Avenue to form a crosstown route.[22] Damen Tower, serving the Humboldt Park branch divergence, was rebuilt with the expectation that it also would switch trains between the subway and the elevated, in the same manner as the State Street subway supplementing the earlier elevated North Side main line,[23] and as late as 1949 commuters were promised such a setup that would have preserved the old Logan Square trackage.[24] However, the CTA had no interest in operating either the old Logan Square elevated or the Humboldt Park branch; the new Damen Tower would never be installed with switching equipment, and the Logan Square branch south of Damen would be closed after the subway opened.[23]

World War II interrupted the construction of the subway; although the federal government allowed the continued construction of the State Street subway, it did not do so for the Dearborn subway despite its being 82 percent complete in 1942.[25] After the war ended, work resumed on the Dearborn subway and it opened at the midnight beginning Sunday, February 25, 1951.[25] The subway was predicted to reduce the travel time between Logan Square and downtown from 28 minutes to 15.[25] Since construction had not started on the Congress Line, trains in the subway turned back at its southern terminus at LaSalle.[25] Despite this incomplete state, and complaints from riders no longer given a direct trip to the Near West Side,[26][27] the new subway had over 60 percent higher ridership than the old Logan Square branch by the end of the year.[28] The subway contains a station of its own on Grand Avenue.[25]

The old Logan Square branch trackage south of its entrance to the subway became known as the Paulina Connector, connecting the branch with the rest of the "L" system now that it no longer had revenue service to the Loop.[29] Construction on the Congress Line began in 1954, leaving the Douglas branch with the issue of how to connect with the Loop in the meantime.[30] The Paulina Connector south of Washington Boulevard (about one-half mi (0.80 km) south of Grand) was reopened for the purpose,[30] but the Metropolitan's old tracks north of Washington were replaced in revenue service by a direct connection to the Lake Street Elevated's trackage known as Washington Junction.[29] This connection was used until the Congress Line was completed in 1958, after which the Douglas branch connected directly with it to use the Dearborn Street subway to go downtown, creating the "West-Northwest Route"[31] that was renamed the Blue Line in 1992.[32]

Wooden parts from the old stations on the Connector, including Grand, were removed to reduce fire hazards, as were the lowest flights of stairs to deter trespassing.[33] North of Washington Junction, the old northbound track was removed in 1957 while the southbound track continued non-revenue operations.[29] The portion of the Connector north of Kinzie Street, including where Division, Chicago, and Grand stations stood, was demolished in 1964 and the right of way sold to adjacent landowners.[34]

As originally opened, the Metropolitan's trains ran every six minutes between 6 a.m. and 6:30 p.m., and every ten minutes during the night, on the main line and Northwest branch; the average speed was 16 mph (26 km/h).[11] By 1898, the night hours were updated so that trains ran at 30-minute intervals on each branch, or 15 minutes on the Northwest branch.[6] Fare control was usually by a station agent posted 24 hours a day, but conductors were used instead on the Northwest branch during night and off-peak hours from 1931 to 1934, and during 1936 and 1937.[36]

Grand Avenue had streetcar routes as early as 1912, which were consolidated in 1916 to a single line with Navy Pier as its eastern end.[37] By 1928, this route had owl service between 1 and 5 a.m., wherein cars ran once every thirty minutes;[38] during the day, streetcar lines in Chicago typically had intervals of between eight and fifteen minutes per car.[39] Service was cut back from Navy Pier in 1941, and buses began supplementing streetcars in 1949, replacing them altogether in 1951 shortly after the station's abandonment.[40]

Grand's ridership peaked in 1902 at 634,530 passengers.[41] Between 1900 and 1913, the station was consistently in the middle of the Northwest branch's[lower-alpha 1] rankings, surpassing the stations of Lake and Madison to its south but trailing Robey, Division, and Chicago to its north.[42] By the late 1910s, the station was the lowest-ridership station on the branch except for the Metropolitan's portion of the Lake Street Transfer station, the successor to Lake and a station whose ridership the Metropolitan shared with the Lake Street Elevated, giving a combined ridership higher than that of Grand; in any event, Grand's ridership also trailed every station on the Logan Square branch proper.[43] Ridership last exceeded 600,000 passengers in 1907, 500,000 in 1910, 400,000 in 1912, 300,000 in 1924, and 200,000 in 1929.[7] During the 1930s, ridership dropped below six figures, bottoming out at 83,003 patrons in 1933.[36] In the last year ridership records are available, 1948, Grand served 128,950 passengers, a 23.27 percent decrease from the 168,006 in 1947.[44] In 1948, it was the 196th-most ridden of the 223 stations on the Chicago "L" at the beginning of the year where ridership was recorded; in 1947, it had been the 193rd-most ridden of 222 such stations.[lower-alpha 2][47]