Capital: Springfield(
)
Land Area: 55,584 sq. miles
(source: 2010 Census)
Population: 12,830,632
(source: 2010 Census estimate)
Highest Point:
Charles Mound at 1,235 feet, located in the county/subdivision of Jo Daviess
(source: U.S. Geological Survey)
Lowest Point:
Mississippi River at 279 feet, located in the county/subdivision of Alexander
(source: U.S. Geological Survey)
Geographic Center:
Located in Logan County approx. 28 miles northeast of Springfield
(source: U.S. Geological Survey)