This line contains the oldest stretch of track in Wisconsin, constructed by an early incarnation of the CMStP&P, the Milwaukee and Mississippi Railroad.

[4] In 1935, the Milwaukee Road introduced the Hiawatha passenger train which ran at high speed between Saint Paul, Minnesota, and Chicago.

[5] When Amtrak took over passenger service in the United States in 1971, the former Great Northern Empire Builder was redirected to run along the Hiawatha's route between Chicago and Minneapolis–Saint Paul, Minnesota.

The Amtrak Hiawatha, which now runs between Milwaukee and Chicago, was expected to be extended to Madison with stops in Watertown, Brookfield, and possibly another city.

[6][7] However, these plans never came to fruition following then governor Scott Walker returning the funds to the federal government for use on passenger rail projects in other states.