Corps badges in the American Civil War were originally worn by soldiers of the Union Army on the top of their army forage cap (kepi), left side of the hat, or over their left breast.
The idea is attributed to Maj. Gen. Philip Kearny, who ordered the men in his division to sew a two-inch square of red cloth on their hats to avoid confusion on the battlefield.
This idea was adopted by Maj. Gen. Joseph Hooker after he assumed command of the Army of the Potomac, so any soldier could be identified at a distance.
Maj. Gen. Daniel Butterfield, Hooker's chief of staff, was assigned the task of designing a distinctive shape for each corps badge.
The badges eventually became part of the Army regulations and a great source of regimental pride.
Co C 110th Pennsylvania Infantry after the Battle of Fredericksburg Va. An excellent photograph showing the Union Army white Diamond shaped III Corps Badges on the forage caps
Union Army 1st Division Flag, I Corps
Union Army 2nd Division Flag, I Corps
Union Army 3rd Division Flag, I Corps
Union Army 1st Division Flag, II Corps, Army of the Potomac
Union Army 2nd Division Flag, II Corps, Army of the Potomac
Union Army 3rd Division Flag, II Corps, Army of the Potomac
Union Army Corps Hqr's, II Corps, Army of the Potomac
Union Army Artillery Brigade, II Corps, Army of the Potomac
Union Army Quartermaster Badge, II Corps, Army of the Potomac
Union Army 4th Division Badge, II Corps
Union Army 1st Division Flag, III Corps
Union Army 2nd Division Flag, III Corps
Union Army 3rd Division Flag, III Corps
Union Army 4th Division Badge, III Corps
Union Army 1st Division Flag, IV Corps
Union Army 2nd Division Flag, IV Corps
Union Army 3rd Division Flag, IV Corps
Union Army 1st Division Flag, V Corps
Union Army 2nd Division Flag, V Corps
Union Army 3rd Division Flag, V Corps
Union Army 1st Division Flag, VI Corps
Union Army 2nd Division Flag, VI Corps
Union Army 3rd Division Flag, VI Corps
Union Army 4th Division Badge, VI Corps
Union Army 1st Division Badge, VII Corps
Union Army 2nd Division Badge, VII Corps
Union Army 3rd Division Badge, VII Corps
Union Army 1st Division Badge, VIII Corps
Union Army 2nd Division Badge, VIII Corps
Union Army 3rd Division Badge, VIII Corps
Union Army 1st Division Badge, IX Corps
Union Army 2nd Division Badge, IX Corps
Union Army 3rd Division Badge, IX Corps
Union Army 4th Division Badge, IX Corps
Union Army 1st Division Badge, X Corps
Union Army 2nd Division Badge, X Corps
Union Army 3rd Division Badge, X Corps
Union Army 1st Division Badge, XI Corps
Union Army 2nd Division Badge, XI Corps
Union Army 3rd Division Badge, XI Corps
Union Army 1st Division Badge, XII Corps
Union Army 2nd Division Badge, XII Corps
Union Army 3rd Division Badge, XII Corps
Union Army 1st Division Badge, XIV Corps
Union Army 2nd Division Badge, XIV Corps
Union Army 3rd Division Badge, XIV Corps
Union Army 1st Division Badge, XV Corps
Union Army 2nd Division Badge, XV Corps
Union Army 3rd Division Badge, XV Corps
Union Army 4th Division Badge, XV Corps
Union Army Headquarters Badge, XV Corps
Union Army 1st Division Badge, XVI Corps
Union Army 2nd Division Badge, XVI Corps
Union Army 3rd Division Badge, XVI Corps
Union Army 1st Division Badge, XVII Corps
Union Army 2nd Division Badge, XVII Corps
Union Army 3rd Division Badge, XVII Corps
Union Army 1st Division Badge, XVIII Corps
Union Army 2nd Division Badge, XVIII Corps
Union Army 3rd Division Badge, XVIII Corps
Union Army 1st Division Badge, XIX Corps
Union Army 2nd Division Badge, XIX Corps
Union Army 3rd Division Badge, XIX Corps
Union Army 1st Division Badge, XX Corps
Union Army 2nd Division Badge, XX Corps
Union Army 3rd Division Badge, XX Corps
Union Army 4th Division Badge, XX Corps
Union Army 1st Division Badge, XXI Corps
Union Army 2nd Division Badge, XXI Corps
Union Army 3rd Division Badge, XXI Corps
Union Army Headquarters Badge, XXI Corps
Union Army 1st Division Badge, XXII Corps
Union Army 2nd Division Badge, XXII Corps
Union Army 3rd Division Badge, XXII Corps
Union Army 1st Division Badge, XXIII Corps
Union Army 2nd Division Badge, XXIII Corps
Union Army 3rd Division Badge, XXIII Corps
Union Army 1st Division Badge, XXIV Corps
Union Army 2nd Division Badge, XXIV Corps
Union Army 3rd Division Badge, XXIV Corps
Union Army 1st Division Badge, XXV Corps
Union Army 2nd Division Badge, XXV Corps
Union Army 3rd Division Badge, XXV Corps
Union Army I Corps, 1st Division Badge, 1st Brigade
Union Army I Corps, 2nd Division Badge, 1st Brigade
Union Army I Corps, 3rd Division Badge, 1st Brigade
Union Army I Corps, 1st Division Badge, 2nd Brigade
Union Army I Corps, 2nd Division Badge, 2nd Brigade
Union Army I Corps, 3rd Division Badge, 2nd Brigade
Union Army I Corps, 1st Division Badge, 3rd Brigade
Union Army I Corps, 2nd Division Badge, 3rd Brigade
Union Army I Corps, 3rd Division Badge, 3rd Brigade