Henry Leaming rose from captain to major and lieutenant colonel of the 40th Indiana Infantry, assuming regimental command after Lieutenant Colonel Elias Neff was wounded at Stones River. He led the 40th during the brutal Missionary Ridge assault, sustaining a knee wound from enemy fire but remaining in command, and continued through the Atlanta Campaign, Franklin, and Nashville. Promoted to colonel in May 1865, he mustered out with his veteran regiment.