Jefferson Barracks was established in 1826 as the country’s first “Infantry School of Practice.” It was named in honor of former President Thomas Jefferson. It served as a major United States military installation until 1946 and played an important role in the Unites States westward expansion.During its early years, Ulysses S. Grant, Robert E. Lee, Jefferson Davis, and William T. Sherman were but a few of the famous U.S. Army officers who served there.Jefferson Barracks served as a gathering point for troops and supplies bound for service in the Seminole Wars, the Mexican War, the Civil War, various Indian wars in the West, the Spanish-American War, and World Wars I and II. Jefferson Barracks also served as the first basic training site for the U.S. Army Air Corps during WWII.Jefferson Barracks has several buildings remaining from the 1800s, such as a Laborer’s House and Ordnance Stable built in 1851, a Visitor Center built in 1878, and two Powder Magazines which stored the ammunition for the post. The old powder magazines are now used as free museums open Wednesday through Sunday from noon to 4 p.m.The Ordnance Room, built in 1851, features exhibits relating to specific aspects of Jefferson Barracks and U.S. military history – the current exhibit is “Courageous and Faithful: The U.S. Cavalry at Jefferson Barracks – while the Powder Magazine Museum features exhibits relating to the 120 year history of Jefferson Barracks as an active post.In 1971, Jefferson Barracks County Historic Park, the adjacent active Missouri National Guard Base, and other adjacent parcels were placed on the National Register of Historic Places. The park site is located in south St. Louis County on bluffs overlooking the Mighty Mississippi.