DM&E 12th Street Bridge

In 1864, 50 miles of new railroad was completed from Winona to Rochester, Minnesota by the Winona and Saint Peter Railway (W&StP). The following year, an additional 55 miles was completed to Waseca. The Chicago & North Western Railway (C&NW) would purchase a controlling stake in the W&StP in 1867. Construction would continue in 1870, with an additional 11 miles completed between Waseca and Janesville. The following year, 23 additional miles were opened to Mankato, followed by 30 additional miles completed to New Ulm in 1872. 62 more miles were completed to Tracy, Minnesota in 1879.
From Tracy, the route would be continued westwards in 1879, with numerous branch lines built off the main line. In 1900, the Mankato & New Ulm Railway (M&NU) would complete a new route, 26 miles in length between Mankato and New Ulm. This new line bypassed the old line, which used two large iron bridges to cross the Minnesota River. The W&StP and M&NU would be consolidated into the C&NW in June 1900. The C&NW operated this route as the main line of the Dakota Division, eventually operating the passenger train the "Dakota 400" over the route. Because the original line between Mankato and New Ulm was not considered necessary, the line was abandoned in stages. The first segment abandoned was between Burdette (Mankato) and Kasota, followed by the Kasota to St. Peter segment in 1957. The line was further abandoned between St. Peter and Traverse in 1963, and between Traverse and the New Ulm Quarry in 1970.
As the line became less profitable in the 1970s and 1980s, the C&NW was considering abandoning the route. In 1986, the line between Winona and Rapid City, South Dakota would be sold to the Dakota, Minnesota & Eastern Railroad. The DM&E would be purchased by Canadian Pacific Railway (CP) in 2008. In 2023, CP merged with Kansas City Southern to form Canadian Pacific Kansas City Limited, commonly known as CPKC. CPKC continues to operate the Waseca to Tracy segment as the Tracy Subdivision.