The Northwestern Elevated Railroad was the last of the privately constructed rapid transit lines to be built in Chicago.

The Northwestern Elevated Railroad Company was incorporated on October 30, 1893,[2][3] and on January 8, 1894, it was granted a 50-year franchise by the City of Chicago.

[4] The original franchise stipulated that service between a downtown location to the south of the Chicago River and Wilson Avenue was to begin by December 31, 1897.

[14] Service was extended 7 miles (11 km) north from the Wilson terminal to Central Street in suburban Evanston in May 1908.

[16] The Milwaukee Road depots at Argyle Park, Edgewater, North Edgewater, Rogers Park, Birchwood, Calvary, Main, Dempster, Davis, Noyes and Central were demolished and the tracks spread to allow their replacement with new temporary island platform stations.