In 1898, the Salvadoran Army selected a hill in San Salvador to begin construction of a metal galley, and later a wooden structure, to house soldiers of the Legion of Freedom.

[1] During the barracks' usage by the army, it served as the operational headquarters for the 1st Artillery Regiment and later the Armed Forces Transmission Support Command.

On 7 January 2003, the remains of Manuel José Arce, a Salvadoran politician who served as the first president of the Federal Republic of Central America from 1825 to 1829, were interred at the military museum.

[2] The museum has several vehicles, aircraft, and up to 35,000 pieces of military equipment — including uniforms, documents, photographs, paintings, insignia patches, statues, and flags — on display.

The Memorial Plaza of National Sovereignty and the Commemorative Monument of the Salvadoran Leaders of Central American Independence are located at the military museum.