The fort was first built during the Indian Wars. It is designated as a National Historic Landmark and serves as home of the United States Army Field Artillery School as well as the Marine Corps' site for Field Artillery MOS school, United States Army Air Defense Artillery School, the 31st Air Defense Artillery Brigade, and the 75th Field Artillery Brigade. Fort Sill is also one of the four locations for Army Basic Combat Training. It has played a significant role in every major American conflict since 1869.