Fort Stockton was established on the top of Presidio Hill in Nov. 1846 by Commodore Robert F. Stockton to defend the city during the Mexican War. The base was also known as Fort duPont after sailors and Marines from the USS Cayne under the command of Samuel F. duPont raised the flag over San Diego July 29, 1846. The base house the Mormon Battalion and seven artillery pieces. The based ended with the departure of troops in September 1848.
Point Loma became the home of a military reservation by Executive Order Feb. 26, 1852, located on the southern side three miles long. This area included Ballast Point where the Spaniards had built Fort Guijarros in 1799. The Army established Fort Rosecrans in 1899 and it remained an Army base until transfer to the Navy in 1959 for the purpose of building a submarine base on Ballast Point that was established Oct. 23, 1963.