51st Illinois Volunteer Infantry Regiment

51st Regiment Illinois Volunteer Infantry "Chicago Legion"
Illinois state flag
Active	December 24, 1861, to September 25, 1865
Country	United States
Allegiance	Union
Branch	Infantry
Engagements	Battle of Island Number Ten Battle of Stone's River Battle of Chickamauga Battle of Resaca Battle of Kennesaw Mountain Siege of Atlanta Battle of Jonesboro Battle of Franklin Battle of Nashville

The 51st Regiment Illinois Volunteer Infantry was an infantry regiment that served in the Union Army during the American Civil War.

The 51st Illinois Infantry was organized at Chicago, Illinois and mustered into Federal service on December 24, 1861.

The regiment was mustered out on September 25, 1865.

The regiment suffered 9 officers and 106 enlisted men who were killed in action or mortally wounded and 1 officer and 134 enlisted men who died of disease, for a total of 250 fatalities.