Established in 1826 ten miles south of St. Louis and named for Thomas Jefferson, Jefferson Barracks became the oldest continuously operating U.S. military post west of the Mississippi River and served first as a recruiting center and training ground. Troops from the post fought in the Black Hawk War of 1831-1832, and the vast distances of frontier patrols helped lead to the creation there in 1833 of the United States Regiment of Dragoons, later redesignated in 1861 as the 1st Cavalry, which by the end of the 19th century had served in the Seminole, Mexican, Civil, and Spanish-American Wars as well as Indian expeditions involving the Cherokee, Iowa, Kansas, Mahas, Pawnee, Potawatomi, Osage, Otoe, Sac, and Sioux. During the American Civil War, Jefferson Barracks became a Union recruiting depot, convalescence center, and military hospital site, with construction of Western Sanitary Commission hospital facilities beginning in April 1862 and more than 26,000 soldiers treated there by war's end; the grounds formed the largest military hospital complex west of the Mississippi River and were part of a wider St. Louis network of wartime hospitals that received casualties from Wilson's Creek, Fort Donelson, Shiloh, Vicksburg, and other fighting along the western rivers, including by hospital ships. Centered on its historic parade ground, Jefferson Barracks was also notable for the extraordinary number of future Civil War leaders stationed there, estimated at 220 generals at one time or another, among them Ulysses S. Grant, William T. Sherman, George H. Thomas, Don Carlos Buell, Philip Sheridan, Albert Sidney Johnston, Joseph E. Johnston, William Hardee, Earl Van Dorn, Braxton Bragg, Robert E. Lee, James Longstreet, George E. Pickett, Lewis Armistead, John Bell Hood, Richard S. Ewell, J.E.B. Stuart, Winfield Scott Hancock, John Sedgewick, John Buford, and Jefferson Davis. Longstreet, born in 1821 and graduated from West Point in 1842, served at Jefferson Barracks as Grant did after arriving on September 30, 1843; the two became friends, Longstreet attended Grant's 1848 wedding in St. Louis, later commanded the Confederate corps that launched Pickett's Charge at Gettysburg, became a Republican after the war, served as Minister to Turkey in 1880 by Grant's appointment, and remained Grant's friend until Grant's death in 1885 before dying in Gainesville, Georgia, in 1904.
