The line had previously been owned by the
Chicago, Milwaukee, St. Paul and Pacific Railroad, commonly known as the Milwaukee Road. It once carried the Milwaukee Road's fast
Hiawatha passenger trains, including trains that regularly exceeded . For several years in the 1940s and early 1950s, trains were scheduled to run along this stretch in 75 minutes or less. The line between Rondout, Illinois and Chicago Union Station fell under the control (not the ownership) of the Northeast Illinois Regional Commuter Rail Corporation in 1982, five years after the Milwaukee filed for its last bankruptcy (though the Milwaukee Road retained ownership of the line between Chicago Union Station and Rondout until 1986). Metra was formed in 1984 and bought the line from the Soo Line Railroad in 1987, with the latter continuing to operate freight trains thereafter via trackage rights. This continued until the Soo was usurped by the Canadian Pacific Railway in 1990. Thirty-three years later, CP amalgamated with the
Kansas City Southern Railway to form
Canadian Pacific Kansas City, or CPKC. While stricter regulations eventually reduced the speed limit to along this stretch, plans are in place to improve the line to support speeds up to —modestly faster than historic trains that used the route. ==References==