The St. Louis Southwestern, known by its nickname of "The Cotton Belt Route" or simply the Cotton Belt, was organized on January 12, 1891, although it had its origins in a rail line founded in 1871 in Tyler, Texas that eventually connected northeastern Texas to Arkansas and southeastern Missouri.

[1] However, that line promptly went into receivership, and was purchased by the St. Louis, Arkansas and Texas Railway in 1886.

[3] The St. Louis Southwestern of Texas merged with the property of the Tyler Southeastern Railway on October 6, 1899.

The Interstate Commerce Commission authorized St. Louis Southwestern Railway to lease the Texas company in December 1953.

The St. Louis Southwestern Railway of Texas was leased to its corporate parent on March 1, 1954.