How it started
Chicago, Milwaukee, St. Paul and Minneapolis Railroad
The railroad that became the Milwaukee Road began as the Milwaukee and Waukesha Railroad in Wisconsin, whose goal was to link the developing Lake Michigan port City of Milwaukee with the Mississippi River. The company incorporated in 1847, but changed its name to the Milwaukee and Mississippi Railroad in 1850 before construction began. Its first line, 5 miles (8.0 km) long, opened between Milwaukee and Wauwatosa, on November 20, 1850. Extensions followed to Waukesha in February 1851, Madison, and finally the Mississippi River at Prairie du Chien in 1857.
As a result of the financial panic of 1857, the M&M went into receivership in 1859 and was purchased by the Milwaukee and Prairie du Chien Railroad in 1861. In 1867, Alexander Mitchell combined the M&PdC with the Milwaukee and St. Paul (formerly the La Crosse and Milwaukee Railroad Company) under the name Milwaukee and St. Paul. Critical to the development and financing of the railroad was the acquisition of significant land grants. Prominent individual investors in the line included Alexander Mitchell, Russell Sage, Jeremiah Milbank, and William Rockefeller.
In 1874, the name was changed to Chicago, Milwaukee and St. Paul Railway Company after constructing an extension to Chicago in 1872. The company absorbed the Chicago and Pacific Railroad Company in 1879, the railroad that built the Bloomingdale Line (now The 606) and what became the Milwaukee District West Line as part of the 36-mile Elgin Subdivision from Halsted Street in Chicago to the suburb of Elgin, Illinois. In 1890, the company purchased the Milwaukee and Northern Railroad; by now, the railroad had lines running through Wisconsin, Minnesota, Iowa, South Dakota, and the Upper Peninsula of Michigan.
The corporate headquarters were moved from Milwaukee to the Rand McNally Building in Chicago, America's first all-steel framed skyscraper, in 1889 and 1890, with the car and locomotive shops staying in Milwaukee. The company's general offices were later located in Chicago's Railway Exchange building (built 1904) until 1924, at which time they moved to Chicago Union Station.
Pacific Extension
From Wikipedia’s article on Chicago, Milwaukee, St. Paul and Pacific Railroad, shared under CC BY-SA 4.0.2