Mound City's location at a river crossroads made it strategic to the Union war effort during the Civil War. Near the junction of the Ohio and Mississippi rivers and the confluence of the Ohio, Tennessee, and Cumberland rivers, the Illinois city housed the headquarters of the Union Navy's Mississippi Squadron, with some eighty inland “brown water” vessels, and three ironclad gunboats—the U.S.S. Cairo, Cincinnati, and Mound City—were built there. After the April 7, 1862, Battle of Shiloh in Tennessee, a U.S. General Hospital was erected in Mound City, and a hotel, warehouse, and foundry were also converted into hospitals with 1,500 beds. Union medical personnel used the captured Confederate steamboat Red Rover to carry wounded soldiers from fighting along the Mississippi River to Mound City. Mound City National Cemetery was established in 1864 on a levee-protected 10-acre tract, and by 1871 it held nearly 5,000 graves, including 1,644 dead from Mound City hospitals, others from battlefields and Union garrisons in Illinois, Kentucky, and Missouri, and more than half unidentified remains, among them twenty-seven Confederate prisoners. The cemetery included a flagstaff and four cannon monuments, and its superintendent's lodge, completed in 1880 and designed by the Office of the Quartermaster General, was built of two-color brick with a steep cross-gable roof that allowed a full-height second floor, unlike the mansard-roof, Second Empire-style lodges built at other national cemeteries in the previous decade. A rostrum was added in 1939. At the center of the original cemetery, the elaborate Illinois State Monument, erected in 1874-75, has a classically inspired granite-and-marble base supporting figures of a soldier and sailor and a 15-foot shaft topped by the female figure Liberty. Introduced by Illinois State Rep. Newton B. Casey of Mound City, the bill funding the $25,000 monument honored all soldiers and sailors, known and unknown, who died during the Civil War and were buried there, and more than 2,000 names representing twenty states and the U.S. Army and Navy are engraved on its base.