At the urging of United States Secretary of War Jefferson Davis, land was secured at San Antonio in 1858 for an arsenal. In 1859, the State of Texas added 16 acres, and the arsenal became headquarters for the U.S. Army's department of Texas. Under construction when the Civil War (1861-65) began, this magazine was included in Federal property surrendered in 1861. The building was completed for Confederate Texas by local contractor J.H. Kampmann. Carefully spaced vents and cavities in the walls permitted air circulation and reduced the danger of sparks igniting stored gunpowder. The arsenal supplied arms for south Texas and frontier defense, as well as the Sibley expedition to New Mexico in 1862. Reoccupied by Federal forces in 1865, this became the principal supply depot for the line of Forts defending frontier settlements. It served the U.S. Army until 1947, when the Arsenal was closed. The long, narrow one-story structure features walls of extremely thick ashlar limestone construction. Details include end gables extended above the roofline, lintels which protrude as hood molds, and date stone in relief over the side entry.