By Gerald Sonnenberg
Hecker Camp #443 Secretary

Irish immigrants had a tremendous impact on the American Civil War. They filled Irish regiments both North and South. While the more famous “Irish Brigade” contained regiments from New York, Massachusetts and Pennsylvania like the “Fighting 69th New York,” did you know that Illinois had at least one Irish “brigade” of it’s own?

The 23rd Illinois Volunteer Infantry Regiment, known as the “First Irish” or “Irish ‘Brigade,’” was an infantry regiment that served in the Union Army during the American Civil War. It was organized at Chicago, Illinois and mustered into Federal service on June 15, 1861.

Initially assigned to garrison the town of Lexington, Missouri, the regiment
surrendered after a short siege to a much larger force of pro-secession Missouri State Guard commanded by State Guard Major General Sterling Price at the Siege of
Lexington in September 1861. After being paroled, General John C. Fremont
(commanding the Department of Missouri) had the 23rd Illinois mustered out of
service. But in December, General George McClellan (then supreme commander in chief of all Union armies) had it restored.

After being reconstituted, the regiment left camp in spring 1862 for western
Virginia, where it spent most of the rest of the war stationed there. The 23rd Illinois was one of only a handful of Illinois regiments to fight in the Eastern Theater of the War having participated in General Sheridan’s Shenandoah Valley Campaign, the Siege of Petersburg and the Appomattox Campaign.

The regiment was present for rebel General Robert E. Lee’s surrender at
Appomattox Court House on April 9, 1865.

Pictured above is a guidon; probably a company flag, carried by soldiers in the 23rd Illinois Volunteer Infantry. The guidon is displayed in the Illinois State Military Museum and bears the symbol of the Celtic harp to represent the regiment’s origins as the “Irish Brigade” in Chicago. The guidon is part of the original Memorial Hall collection, donated to the State of Illinois after the Civil War.

The regiment was mustered out on July 24, 1865.