Cotton Belt 819 is a class "L-1" 4-8-4 "Northern" type steam locomotive and is also the official state locomotive of Arkansas. It was completed in 1943 and was the last engine built by the St. Louis Southwestern Railway, which was affectionately known as "The Cotton Belt Route" or simply "Cotton Belt". It was also the last locomotive built in Arkansas. It was restored to operating condition in 1986 and operated in excursion service until October 1993. As of 2023, the locomotive is now located at the Arkansas Railroad Museum, currently being cosmetically restored.

The St. Louis Southwestern Railway Company, 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 operated as a Southern Pacific subsidiary from 1932 until 1992, when its operation was assumed by Southern Pacific Transportation Company.