Walter Leman Mann, lawyer and Confederate officer, was born in Holmes County, Mississippi, on December 16, 1838, the son of William and Esther Steele (Baskins) Mann. Mann came to Texas with his family in 1840 and settled in Corpus Christi. As a young man, he left Corpus Christi to attend the University of Virginia. Following the death of his father in 1857, Mann returned to Corpus Christi to take charge of the family estate. During the winters of 1859 and 1860 he studied medicine and attended medical lectures in New Orleans.
In the spring of 1861 Mann raised a company of cavalry for service in the Confederate army. He served with this unit briefly as first lieutenant before being assigned to the staff of Brig. Gen. Hamilton P. Bee, commander of the lower Rio Grande military district. In 1864 Mann served as lieutenant colonel and colonel of a regiment of cavalry, referred to as both Mann's Cavalry as well as Bradford's Cavalry, assigned to coastal defense in the Galveston area. Mann was with this unit in Galveston at the surrender of the city on June 5, 1865. After the war, Mann remained in Galveston, where he married Eliza McMorris in November 1865. The couple had four children. In Galveston, Mann worked as a merchant and, after passing the state bar in 1869, as an attorney. Mann was among the leaders of the community. He served as first president of the Galveston Men's Guild and assisted in the founding of the Grace Episcopal Church. Mann died in Galveston, Texas, on July 11, 1875, and was buried at Episcopal Cemetery in Galveston.