On January 7, 2011, CTA requested a rehabilitation program for the North Side Main Line.

The North Side Main Line serves the Near North Side, Old Town, Lincoln Park, Lakeview, Wrigleyville, Uptown, Edgewater and Rogers Park neighborhoods of Chicago, and has stops near Wrigley Field and Loyola University.

The line began operation on May 31, 1900, between The Loop and Wilson Avenue as the Northwestern Elevated Railroad.

[2] From 1919 to 1963, the line was also utilized by interurban trains of the Chicago North Shore and Milwaukee Railroad.

The project also caused the elimination of slow zones in which trains accelerate faster than usual.

The five potential stations include Foster, South Boulevard, Jarvis, Lawrence, and Thorndale.

[9] In 2011, CTA planned a scoping process and which they provided public meetings and a comment period.

[10][11] From 2014 to 2018, The Chicago Department of Transportation rebuilt the Wilson station, which serves as a major transfer point between Red and Purple Line Express trains.