Clarksville is named for American Revolutionary War General George Rogers Clark, who lived for a time on a point of land on the Ohio River. Founded in 1783, the town is believed to be the first American settlement in the Northwest Territory of the new United States. Clarksville is a town in Clark County, Indiana, United States, along the Ohio River as a part of the Louisville Metropolitan area. The population was 21,724 at the 2010 census. The town, once a home site to George Rogers Clark, was founded in 1783 and is the oldest American town in the Northwest Territory. The town is home to the Colgate clock, one of the largest clocks in the World and the Falls of the Ohio State Park, a large fossil bed.