Harrisburg ( /hærɪsbɜrɡ/ or /hɛərzbərɡ/) is a city and township in Saline County, Illinois, United States. It is located about 57 miles (92 km) southwest of Evansville, Indiana, 111 miles (179 km) southeast of St. Louis, Missouri. The 2010 population was 9,017, with a township population of 10,790. It is the county seat of Saline County. Harrisburg is included in the Illinois-Indiana-Kentucky Tri-State Area and is the principal city in the Harrisburg Micropolitan Statistical Area with a combined population of 24,913.
Located at the concurrency of U.S. Route 45, Illinois Route 13, Illinois Route 145, and Illinois Route 34, Harrisburg is known as the "Gateway to the Shawnee National Forest", and was made infamous for the Ohio River flood of 1937, the old Crenshaw House (also known as the Old Slave House), the Tuttle Bottoms Monster, and prohibition era gangster Charlie Birger. A Cairo and Vincennes Railroad boomtown, the city was one of the leading bituminous coal mining distribution hubs of the American Midwest between 1900 and 1937.