Jeffersonville ( /dʒɛfərsənvɪl/) is a city in Clark County, Indiana, along the Ohio River. Locally, the city is often referred to by the abbreviated name Jeff. It is directly across the Ohio River to the north of Louisville, Kentucky along I-65. The population was 44,953 at the 2010 census. The city is the county seat of Clark County.
In 1786 Fort Finney was situated where the Kennedy Bridge is today, to protect the area from Indians, and a settlement grew around the fort. The fort was renamed in 1791 to Fort Steuben, to honor Baron von Steuben. In 1793 the fort was abandoned. Precisely when the settlement became known as Jeffersonville is unclear, but it was probably about 1801. In 1802 local residents used a grid pattern designed by Thomas Jefferson for the formation of a city, and Indiana Territorial Governor William Henry Harrison decided to name the new city after Jefferson. Jeffersonville would be the only city ever designed by Jefferson. On September 13, 1803, a post office was established in the city. In 1808 Indiana's second federal land sale office was established in Jeffersonville, after the first was established in Vincennes in 1807, initiating the growth of the white population in Indiana that was further spurred by the end of the War of 1812.
Shortly after formation, Jeffersonville was named to be the county seat of Clark County in 1802, replacing Springville. In 1812 Charlestown was named the county seat, but the county seat returned to Jeffersonville in 1878, where it remains.