Corps badges in the American Civil War were originally worn by soldiers of the Union Army on the top of their army forage cap, left side of the hat, or over their left chest pocket. The idea was suggested by Major Geneneral Philip Kearny. During a battle he reprimanded officers that turned out to not be under his command. To prevent that from happening again, he ordered the men in his division to sew a  square of red cloth on their hats. This idea was adopted by Major General Joseph Hooker after he assumed command of the Army of the Potomac. This was so any soldier could be identified at a distance.

Corps badges 
Maj. Gen. Daniel Butterfield, Hooker's chief of staff, was assigned the task of designing a distinctive shape for each corps badge. Butterfield also decided that each division in the corps should have a variation of the corps badge in a different color. Division badges were colored as follows:
 Red — First division of corps
 White — Second division of corps
 Blue — Third division of corps
These were used in the United States' Army of the Potomac. These rules were adopted by other Union Armies, however it was not universal.  For example, the XIII Corps never adopted a badge. Also, the XIX Corps had the first division wear a red badge, the second division wear a blue badge, and the third division wear white.

For Army corps that had more than three divisions, the standardization was lost:
 Green — Fourth division of VI, IX, and XX Corps
 Yellow — Fourth division of XV Corps (reportedly Orange was also used for a 5th Division Badge)
 Multicolor — Headquarters or artillery elements (certain corps)

The badges for enlisted men were cut from colored cloth. Officer's badges were privately made and of a higher quality. Metallic badges were often made by jewelers and were personalized for the user. The badges eventually became part of the Army regulations and a great source of regimental pride.

Corps badges
Corps flags
 I II III IV V VI VII VIII IX X XI XII XIV XV XVI XVII XVIII
XIX XX XXI XXII XXIII XXIV XXV Cavalry corps
See also
External links

Corps badges gallery

Corps flags, Army of the Potomac

I Corps, Army of the Potomac

II Corps, Army of the Potomac

III Corps, Army of the Potomac

IV Corps, Army of the Potomac

V Corps, Army of the Potomac

VI Corps, Army of the Potomac

IX Corps, Army of the Potomac

XI Corps, Army of the Potomac

XII Corps, Army of the Potomac

Corps flags, other Union armies

VII Corps, Dept of Arkansas

VIII Corps, Middle Department

X Corps, Department of South

XIII Corps, Army of the Tennessee
No badge was designated for the XIII Corps.

XIV Corps, Army of the Cumberland

XV Corps, Army of the Tennessee

XVI Corps, Military Division of West Mississippi

XVII Corps, Army of the Tennessee

XVIII Corps, Army of the James

XIX Corps, Middle Military Division

XX Corps, Army of the Cumberland 

{Note:XX Corps Badges same as the old XII Corps; the XX Corps was consolidated from the XI and XII Corps}

XXI Corps

XXII Corps, Dept of Washington

XXIII Corps, Dept of Ohio & Dept of North Carolina

XXIV Corps, Dept of Virginia

XXV Corps, Army of the James, Dept of Texas

Brigade badges 
I Corps, Army of the Potomac

Related pages 
Major organizations of the Union Army
Kearny Cross

References

Other websites 
  Designs of Civil War Corps Badges
 Civil war insignia cavalry, infantry and artillery brass

Union Army