Evans was commissioned as major of the 31st Georgia Infantry on November 19, 1861, and was promoted to colonel on May 13, 1862, fighting in the Seven Days Battles, Second Manassas, and Antietam. He had temporary command of Alexander Lawton's Georgia brigade from September until November 1862, seeing additional action at Fredericksburg. During the Gettysburg Campaign and the 1864 fighting at the Wilderness and Spotsylvania, Evans again commanded the 31st Georgia while John Brown Gordon commanded the brigade.