The CITADEL' The CITADEL is a military college located in Charleston, South Carolina. It is the oldest military college in the United States and was founded in 1842. The CITADEL is known for its rigorous academic and military training programs, and it is one of the few remaining senior military colleges in the country. The CITADEL is also home to the South Carolina Corps of Cadets, which is the largest uniformed student body in the United States.