 One infantry regiment, the Third Arkansas, served in the eastern theater for the duration of the war, thus making it the state's most celebrated Confederate military unit.Attached to General Robert E. Lee's Army of Northern Virginia, the Third Arkansas would take part in almost every major Eastern battle, including the Battle of Seven Pines, Seven Days Battle, Battle of Harper's Ferry, Battle of Antietam, Battle of Fredericksburg, Battle of Gettysburg, Battle of Chickamauga, Battle of the Wilderness, and the Appomattox Campaign.Once Arkansas left the Union in May 1861, the existing volunteer militia companies were among the first mustered into state service and be formed into new volunteer infantry regiments, also referred to as "State Troops".