St. Louis Southwestern

St. Louis Southwestern Railway

Cotton Belt system as of 1918
Reporting mark	SSW
Locale	Arkansas, Illinois, Louisiana, Missouri, and Texas
Dates of operation	1891–1992
Successor	Southern Pacific
Track gauge	4 ft 8 1⁄2 in (1,435 mm) standard gauge
Headquarters	St. Louis, Missouri

The St. Louis Southwestern Railway (reporting mark SSW), known by its nickname of "The Cotton Belt Route" or simply Cotton Belt, is a former US Class I railroad which operated between St. Louis, Missouri, and various points in the states of Arkansas and Texas from 1891 to 1992.

The Cotton Belt was one of the lines comprising the railroad empire acquired by financier Jay Gould in the last quarter of the 19th century; according to the Handbook of Texas, "By 1890 Gould owned the Missouri Pacific, the Texas and Pacific, the St. Louis Southwestern, and the International-Great Northern, one-half of the mileage in the Southwest."

The railroad was organized on January 15, 1891, although it had its origins in a series of short lines founded in Tyler, Texas, in 1870 that connected northeastern Texas to Arkansas and southeastern Missouri. Construction of the original Tyler Tap Railroad began in the summer of 1875.

On October 18, 1903, the Cotton Belt gained trackage rights via the Thebes Bridge and the Missouri Pacific Railroad along the eastern shore of the Mississippi River to reach East St. Louis, Illinois, and then used Terminal Railroad Association trackage rights into St. Louis. The Cotton Belt also operated a yard and a locomotive servicing facility in East St. Louis, just east of Valley Junction, and south of Alton and Southern Railroad's Gateway Yard, and north of Kansas City Southern's East St. Louis Yard. They also had a freight station in downtown St. Louis. Union Pacific Railroad now operates the yard (still named "Cotton Belt Yard"), but the engine servicing facilities have been demolished.