William F. Fox, Lt. Col. U. S. V., Regimental Losses in the American Civil War, 1861-1865: A Treatise on the extent and nature of the mortuary losses in the Union regiments, with full and exhaustive statistics compiled from the official records on file in the state military bureaus and at Washington

Twelfth Missouri Infantry.

Total enrollment, 931; killed, 112; percentage, 12.0.

notes.--Organized at St. Louis in August, 1861. After participating in Fremont's expedition in Missouri, the regiment left its camp at Rolla, Mo., in January, 1862, with General Curtis's Army, moving into Arkansas, where it was engaged, March 8, 1862, at the battle of Pea Ridge. It was then in Greusel's Brigade, of Osterhaus's Division. The rest of that year was passed in Southern Missouri and Northern Arkansas, its next battle occurring, December 29, 1862, at Chickasaw Bluffs; a few days after it sailed for Arkansas Post, where it was present but not engaged. It was then in Hovey's Brigade, of Steele's Division. During the Vicksburg campaign it was in C. R. Woods's Brigade, Steele's Division, Fifteenth Corps. It took a prominent part in the assault on Vicksburg, May 22, 1863, in which Major Gustavus Lightfoot was killed. After the fall of Vicksburg, the regiment accompanied its corps to Tennessee, where it participated in the battles of Lookout Mountain and Missionary Ridge, in which Colonel Wangelin lost an arm. On May 1, 1864, it moved with Sherman's Army in the advance on Atlanta. It was then in Wangelin's (3d) Brigade, Osterhaus's (1st) Division, Fifteenth Corps; this division was subsequently commanded by General Charles R. Woods. The Twelfth fought its last battle at Ezra Chapel, Ga., on July 28, 1864; its time having expired it was shortly afterwards ordered home for muster-out. Of the officers belonging to the regiment, ten were killed, one lost both eyes, one lost a leg and arm, one lost one arm, and two lost one leg each; one died of disease, and one was drowned.