John Simpson Chisum (August 15, 1824 – December 23, 1884) was a wealthy cattle baron in the American West in the mid-to-late 19th century. He was born in Hardeman County, Tennessee, and moved with his family to Texas in 1837, later finding work as a building contractor. He also served as county clerk in Lamar County. He was of Scottish, English, and Welsh descent.In 1854, Chisum became engaged in the cattle business and became one of the first to send his herds to New Mexico Territory.