With the Louisville and Nashville Railroad running through Lebanon, the Union army frequently established camps there during the Civil War. In September 1861, Colonel John M. Harlan founded Camp Crittenden and organized the 10th Kentucky Union Infantry at Lebanon. Later, troops led by U.S. General Geo. Thomas camped there before fighting in the Battle of Mill Springs in January 1862. Illness struck Thomas's army, and many men died of typhoid. Lebanon National Cemetery began as a burial ground for these troops. In 1864, more than 2,000 African American recruits, mostly slaves, joined the Union army there. Lebanon was one of the largest African American recruiting grounds in the state, behind Camp Nelson and Louisville.