The largest city in the state of Florida by both population and by area in the contiguous United States, Jacksonville is the county seat of Duval County. It is the principal city in the Jacksonville metropolitan area and has a population of around 1 million residents. Jacksonville is centrally located on the St. Johns River, about 25 miles south of the Georgia state line and about 340 miles north of Miami. Historically, the area was inhabited by the Timucua people, but in 1564 it became the site of the French colony of Fort Caroline. Named after President Andrew Jackson, the city became a major military and civilian deep-water port in the 19th-century.