Louisville is the largest city in the Commonwealth of Kentucky and the 29th most-populous city in the United States. Louisville is the historical seat and, since 2003, the nominal seat of Jefferson County, on the Indiana border.
Named after King Louis XVI of France, Louisville was founded in 1778 by George Rogers Clark, making it one of the oldest cities west of the Appalachians. With nearby Falls of the Ohio as the only major obstruction to river traffic between the upper Ohio River and the Gulf of Mexico, the settlement first grew as a portage site. It was the founding city of the Louisville and Nashville Railroad, which grew into a 6,000-mile system across 13 states.
Today, the city is known as the home of boxer Muhammad Ali, the Kentucky Derby, KFC, the University of Louisville and its Cardinals, Louisville Slugger baseball bats, and three of Kentucky's six Fortune 500 companies: Humana, Kindred Healthcare, and Yum! Brands. Muhammad Ali International Airport, Louisville's main commercial airport, hosts UPS's worldwide hub.
Since 2003, Louisville's borders have been the same as those of Jefferson County, after a city-county merger.