Cairo is located at the confluence of the Mississippi and Ohio Rivers. The rivers converge at Fort Defiance State Park, a Civil War fort that was commanded by General Ulysses S. Grant. Cairo has the lowest elevation of any location within Illinois and is the only city in the state surrounded by levees.
During the American Civil War, Cairo was a strategically important supply base and training center for the Union army. For several months, both General Grant and Admiral Foote had headquarters in the town.
