The original 85-acre tract (gift of Austin citizens in 1892) was the site of annual encampments for the Texas Volunteer Guard, an elite militia constituted in 1876. Because larger maneuver, parade, and drill areas were needed, the guardsmen worked actively to acquire more land. With state and federal purchases, the camp at its largest consisted of over 430 acres.
By vote of guardsmen, the camp was named in 1898 for Adjutant General Woodford Haywood Mabry (1856-1899), who provided forceful leadership for the militia.
In 1914 (after the National Guard was created 1906) the State of Texas built an arsenal here for stores formerly held in the Capitol. This was a campsite for United States Army during the first World War, and was principal site until 1928 for annual guard encampments. During World War II, it was an ordnance engine rebuild station for the United States Army.
For many years, Texas Department of Public Safety patrolmen were trained at Camp Mabry; Texas Rangers had their training command here until 1953. This has been headquarters since 1954 for the state Adjutant General. Other post installations include Texas Army National Guard state officer candidate school and the U.S. Property and Fiscal Office and Warehouse.