highway with the "L" was made in 1939 as part of a grant agreement with the federal government in securing the funding for the State Street and Dearborn Street subways, and the Chicago City Council formally adopted the route on October 31, 1940. In October 1939 it was still planned to have the Congress street extension of the Dearborn Street Subway connect with the elevated structure at Halsted, but it eventually became inevitable that a superhighway plan would necessitate the removal of the main line and Garfield Park branch. World War II interrupted plans to construct the Dearborn Street Subway; although the federal government allowed the continued construction of the State Street Subway, it did not do so for the Dearborn Street Subway. After the City Council designated the Congress street subway an official project of the city on June 13, 1945, it formally authorized its construction on December 30, 1946. Various negotiations between the City, the CTA, Cook County, and the state of Illinois regarding the right-of-way of the project were conducted between 1951 and 1954. In the final settlement of those negotiations, the City assumed responsibility for the expressway and rapid transit facilities in between the Chicago River and Laramie Avenue; in exchange, the CTA granted the City and Cook County a permanent easement on the right-of-way of the Metropolitan main line and Garfield Park branch between Desplaines Street and Sacramento Boulevard to construct the facilities, and agreed to demolish the elevated structures at its own expense. The Dearborn Street Subway opened on February 25, 1951, and the Logan Square branch was routed through it. As the connection between its terminal at LaSalle and the Congress Street expressway had not yet been constructed, its trains were forced to turn around at LaSalle. The Douglas Park and Garfield Park branches continued to go downtown through the main line. After this point, the main line and Garfield Park branch were formally merged into a single line known as the "Garfield Park Line" or "Garfield Line". Skip-stop service was implemented on the Garfield Line during rush-hour service starting on December 9, 1951. Laflin was closed on that date, but in contrast to other lines such as the Lake Street Elevated and North-South route where the introduction of skip-stop coincided with the mass closure of lightly-used stations, the other stations remained open in anticipation of their demolition. Starting on September 20, 1953,