Illinois in the American Civil War

The U.S. state of Illinois during the American Civil War was a major source of troops for the Union Army (particularly for those armies serving in the Western Theater of the Civil War), and of military supplies, food, and clothing. Situated near major rivers and railroads, Illinois became a major jumping off place early in the war for Ulysses S. Grant's efforts to seize control of the Mississippi and Tennessee rivers. Statewide, public support for the Union was high despite Copperhead sentiment.

Illinois contributed 250,000 soldiers to the Union Army, ranking it fourth in terms of the total manpower in Federal military service. Illinois troops predominantly fought in the Western Theater, although a few regiments played important roles in the East, particularly in the Army of the Potomac. Several thousand Illinoisians were killed or died of their wounds during the war, and a number of national cemeteries were established in Illinois to bury their remains. Besides President Abraham Lincoln, a number of other Illinois men became prominent in the army or in national politics, including Ulysses S. Grant (a resident when the war started), John M. Schofield and the aforementioned John A. Logan. No major battles were fought in the state, although several river towns became sites for important supply depots and "brownwater" navy yards. Several prisoner of war camps and prisons dotted the state after 1863, processing thousands of captive Confederate soldiers.

However, not everyone in the state supported the war. In fact, there were even calls for secession in Southern Illinois or Little Egypt by several residents. In Marion residents voted to secede from the United States. A few, even, volunteered for the Confederate States Army in Tennessee. Thirty-four men, while Frank Metcalf claimed they were forty-five, from the southern tip of the state, were recruited from Jackson and Williamson County, joined Company G, "The Illinois Company", of the 15th Tennessee Regiment Volunteer Infantry. This can be attributed to the region's close cultural and economic ties to the South since many Southerners had migrated there. However, the movement for secession soon fizzled after the proposal was blocked and shelved.

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