During the late 1930's and early 1940's, several city ordinances approved grade separation projects at various individual crossings. Funding was typically either through the Federal Public Works Administration, or through the Motor Fuel Tax Fund.
Around 1927
Opening of Central Ave. viaduct over Milwaukee Road Dubuque & Illinois Division. No ordinance could be found for this viaduct.
Around 1920's-1930's
Opening of Kedzie Ave. viaduct over Belt Railway of Chicago. No ordinance could be found for this viaduct.
July 30, 1931
Ordinance for 103rd St. viaduct over Nickel Plate Road and Chicago & Western Indiana.
December 2, 1936
Ordinance for depressed subway under Baltimore & Ohio Altenheim Line at Laramie Ave. Ordinance amended July 9, 1937, revising plan to a Laramie Ave. viaduct.
July 6, 1938
Ordinance for depressed subway under Milwaukee Road Dubuque & Illinois Division at Austin Ave.
September 28, 1938
Ordinance for 31st St. viaduct over Belt Railway of Chicago.
March 1, 1939
Ordinance for depressed subway under Milwaukee Road Dubuque & Illinois Division at Laramie Ave.
January 11, 1940
Ordinance for depressed subway under Wabash at 79th St. and Kedzie Ave.
October 16, 1941
Ordinance for depressed subway under paralleling Belt Railway of Chicago 59th Street Line and Indiana Harbor Belt Stock Yards Line at Cicero Ave.
December 1, 1941
Ordinance for depressed subway under Belt Railway of Chicago at 47th St.
January 30, 1946
Ordinance for subway under joint Rock Island and New York Central line at Congress St., as part of expressway project.