State, southeastern central U.S. Area: 40,409 sq mi (104,659 sq km). Pop. (2009 est.): 4,314,113. Capital: Frankfort. Kentucky is bordered by Ohio, West Virginia, Virginia, Tennessee, Missouri, Illinois, and Indiana. Among its geographical features are the Appalachian Mountains of the east, the interior lowlands, including the Bluegrass region, and the rich lowlands along the Mississippi River. Before the arrival of white settlers, the region was a hunting ground for Indian tribes, including the Shawnee, Iroquois, and Cherokee. Daniel Boone, among the first white settlers, arrived in 1769; a wave of immigration followed the American Revolution. Settlements began as part of a district of Virginia, but in 1792 Kentucky entered the Union as the 15th state. It was a border state during the American Civil War, remaining in the Union but providing troops to both sides. The opening of rail lines into the eastern coal country and the introduction of a tobacco economy spurred growth in the late 19th century. In the 1970s a nationwide energy shortage created a demand for coal, from which Kentucky prospered, but demand dropped in the 1980s and many jobs were lost. Manufacturing is the leading source of income, while tobacco is the chief crop. Kentucky is known for its bourbon whiskey and Thoroughbred horses; the Kentucky Derby is run annually at Churchill Downs.