Chicago North Shore and Milwaukee Railroad

Chicago North Shore and Milwaukee Railroad

CNS&M 700 near Illinois Route 131 in Lake Bluff, Illinois, circa 1957.
Reporting mark	CNSM
Locale	Northeast Illinois and Southeast Wisconsin
Dates of operation	1916–1963
Predecessor	Chicago & Milwaukee Electric Railway
Track gauge	4 ft 8 1⁄2 in (1,435 mm) standard gauge
Electrification	Overhead wires, 650 V DC Third rail, 600 V DC (Chicago 'L')
Headquarters	Highwood, Illinois

The Chicago North Shore and Milwaukee Railroad, also known as the North Shore Line, was an interurban railway that served the North Shore region of the Chicago metropolitan area, and southeastern Wisconsin. The North Shore Line was formed in 1916, when industrialist Samuel Insull acquired the Chicago and Milwaukee Electric Railway Company. Beginning in 1919, the railroad provided electric freight and passenger service between the Chicago Loop and downtown Milwaukee, Wisconsin. The high standard to which the railroad was built, in conjunction with its fast operating speeds and streamlined Electroliner service led author and rail historian William D. Middleton to deem the North Shore Line a "super interurban".

After World War II, the North Shore Line began to face an irreversible decline in passenger ridership. The company petitioned to end rail service in 1958, and despite several years of legal opposition from an organization of regular commuters, the North Shore Line became the final interurban system to undergo complete abandonment with the end of all rail service in January 1963.

The Chicago Transit Authority Yellow Line currently operates over a portion of the former right-of-way, and several pieces of the railway's have been preserved. Other rail services serve various other former markets of the North Shore Line.