Marshfield was a rapid transit station on the Chicago "L". Constructed by the Metropolitan West Side Elevated Railroad, it was the westernmost station of the Metropolitan's main line, which then diverged into three branches: the northwestern Logan Square branch, the western Garfield Park branch, and the southwestern Douglas Park branch. The station was in service from 1895 to 1954, when it, alongside the main line and the Garfield Park branch, was demolished to make way for the Eisenhower Expressway and rapid-transit Congress Line in its median. In addition to its use on the "L", Marshfield was served by the Chicago Aurora and Elgin Railroad (CA&E), an interurban that used the Garfield Park branch and main line's tracks, between 1905 and 1953.
The Metropolitan was one of four companies that established the "L". With interruptions and financial issues, it operated its lines until 1911, when it handed them over the to Chicago Elevated Railways (CER) trust. The companies forming the CER trust formally merged into the Chicago Rapid Transit Company (CRT) in 1924, which continued operation of the "L" until it was taken over by the publicly-held Chicago Transit Authority (CTA) in 1947. The CA&E, on the other hand, was a descendant of the Aurora Elgin and Chicago Railway (AE&C), which had become bankrupt in the aftermath of World War I and split into the CA&E in 1921.
Substantial revisions to the lines that had been constructed by the Metropolitan had been planned since the 1930s. These projects ended up replacing the Logan Square branch with a subway to go directly downtown, and substituting a rapid transit right of way in the median of the Eisenhower for the main line and Garfield Park branch. The subway opened in 1951, removing Logan Square traffic from Marshfield. Construction then started on the Congress Line, which led to the Garfield Park branch's trackage being replaced by temporary right of way and eliminating its service at Marshfield in 1953; the CA&E also ended service on the affected route at that time. This left Douglas Park trains as the sole users of the Marshfield station until April 1954, when they too used a temporary right of way to go downtown.
The Congress Line opened in 1958; the junction that Marshfield had served was maintained between the new line and the Douglas Park branch, but the station prior to this divergence was located on Racine Avenue, significantly to the east of Marshfield Avenue. An entrance to the Medical Center station on the new line was located on Paulina Street, a block west of Marshfield Avenue.