Noll enlisted in Company D of the 20th Michigan Infantry on August 11, 1862, at the age of 26. With his unit he participated in many battles: Fredericksburg, Horseshoe Bend, Jackson, Vicksburg, Blue Springs, the Siege of Knoxville, the Wilderness, Spotsylvania, North Anna, Cold Harbor, and the Crater. He was wounded at the Crater, and was discharged in July 1865 from Harper Hospital in Detroit, having been promoted to the rank of Sergeant. Three of Noll's wartime diaries describing his experiences are available on microfilm at the University of Michigan's Bentley Historical Library.