Civil War Wiki
90th Regiment Illinois Volunteer Infantry
Illinois state flag
Active September 7, 1862 to June 10, 1865
Country United States
Allegiance Union
Branch Infantry
Equipment Siege of Vicksburg
Battle of Missionary Ridge
Battle of Resaca
Battle of Kennesaw Ridge
March to the Sea
Battle of Bentonville

The 90th Regiment Illinois Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.


The 90th Illinois Infantry was organized at Chicago, Illinois and mustered into Federal service on September 7, 1862.

The regiment was mustered out on June 10, 1865.

Total strength and casualties[]

The regiment suffered 2 officers and 58 enlisted men who were killed in action or who died of their wounds and 1 officer and 87 enlisted men who died of disease, for a total of 148 fatalities.[1]


  • Colonel Timothy O'Meara - killed in action at the Battle of Missionary Ridge.
  • Lieutenant Colonel Owen Stewart - Mustered out with the regiment.[2]

See also[]

  • List of Illinois Civil War Units
  • Illinois in the American Civil War


  1. The Civil War Archive website after Dyer, Frederick Henry. A Compendium of the War of the Rebellion. 3 vols. New York: Thomas Yoseloff, 1959.
  2. Illinois in the Civil war website after Illinois Adjutant General's muster rolls