The branch served the West Town and the Humboldt Park neighborhoods of Chicago and consisted of six elevated stations.

During rush hours, Logan Square and Humboldt trains ran downtown, providing skip-stop service between Damen and Marshfield Junction.

[3] The beginning of the end for the Humboldt Park branch was in 1947 when the CTA was formed to take over from the ailing Chicago Rapid Transit.

This led to a decline in Humboldt ridership as passengers preferred to go to Logan Square to ride trains with the newer cars.

In 1951, the CTA made plans to close the Humboldt Park branch alongside the rerouting of Logan Square trains into the Milwaukee-Dearborn Subway.

As wooden cars were forbidden from operating in the subway due to fire safety concerns, Humboldt Park service was cut off from downtown, and reduced to a full-time Lawndale-Damen shuttle.

Remnants of the junction were still visible in the structure at North Avenue until 1996 when the spans were replaced as part of renovation work on the Blue Line.