Fort Bliss trained thousands of U.S. Soldiers during the Cold War. As the United States gradually came to master the art of building and operating missiles, Fort Bliss and White Sands Missile Range became more and more important to the country, and were expanded accordingly. On 1 July 1957 the U.S. Army Air Defense Center was established at Fort Bliss. Located at this center, in addition to Center Headquarters, are the U.S. Army Air Defense School; Air Defense; the 6th Artillery Group (Air Defense); the 61st Ordnance Group; and other supporting elements. In 1957 Fort Bliss and its anti-aircraft personnel began using Nike Ajax, Nike Hercules, Hawk, Sprint, Chaparral, and Redeye missiles. Fort Bliss took on the important role of providing a large area for troops to conduct live fire exercises with the missiles.