Fort Buchanan was established as a camp in 1923, and named after Brigadier General James A. Buchanan, first commander of the Puerto Rico Regiment of Infantry, US Army, later the 65th Infantry Regiment. The camp and units were intended to defend Puerto Rico and Panama. In the 1920s and 1930s Fort Buchanan became a tropical training area for Army and National Guard troops, artillery range, maneuver area, and supply depot. During WWII it was an intake center for recruits, training camp for citizens, and a processing station for soldiers.


After the war, Fort Buchanan shrank to only several hundred acres, and in 1966 the fort was closed as an army post and came under control of the U.S Navy. It reverted back to army control in 1971, under the Third Army. Since then, control of Fort Buchanan has switched multiple times between different commands. As of 2008, it is under the U.S Northern Command area of operations, and continues to support mission readiness and execution, and serve as a base and command for joint operations with US allies in Latin America.