The St. Louis Southwestern Railway Company (reporting mark SSW), known by its nickname of "The Cotton Belt Route" or simply "Cotton Belt", was a Class I railroad that operated between St. Louis, Missouri, and various points in the U.S. states of Arkansas, Tennessee, Louisiana, and Texas from 1891 to 1980, when the system added the Rock Island's Golden State Route and operations in Kansas, Oklahoma, and New Mexico.

The Cotton Belt was part of the railroad empire acquired by financier Jay Gould in the last quarter of the 19th century.

The Morning Star was the second named train over much of this route, operating out of St. Louis Union Station to Dallas, with a separate Memphis section inaugurated in 1941 to provide a convenient connection with the Southern Railway's Tennessean to and from Washington, D.C., and New York City.

The final operations in Texas involved overnight service between St. Louis and Dallas, with major intermediate stops in Jonesboro, Pine Bluff, Texarkana and Tyler.

The last Cotton Belt passenger train, #8, operated on November 30, 1959, from Pine Bluff, Arkansas, to East St. Louis, Illinois.