Paducah is the county seat of McCracken County, Kentucky, United States. The largest city in the Jackson Purchase region, it is located at the confluence of the Tennessee and the Ohio Rivers, halfway between St. Louis, Missouri, to the northwest and Nashville, Tennessee, to the southeast. The population was 25,024 during the 2010 U.S. Census. Twenty blocks of the city's downtown have been designated as a historic district and listed on the National Register of Historic Places.