The Texas Military Department (TMD) is an executive branch agency of the Texas government. Along with the Texas Department of Public Safety, it is charged with providing the security of Texas, which has the second largest population, border, and economy in the United States. It also provides administration of the Texas Military Forces (TXMF), the principal instrument through which it executes security policy. TXMF currently include the Texas Army National Guard, Texas Air National Guard, and Texas State Guard. It formerly included the Texas Rangers, Texas Army, Texas Navy, and Texas Marines.

Camp Mabry is a military installation in Austin, Texas, housing the headquarters of the Texas Military Department, Texas Military Forces, and Texas Military Forces Museum. Established in 1892, Camp Mabry is the third-oldest active military installation in Texas, behind Fort Sam Houston and Fort Bliss. It was named for Brigadier General Woodford H. Mabry, the Adjutant General of Texas when the camp was founded. The camp was added to the National Register of Historic Places in 1996.