Jacksonville is centered on the banks of the St. Johns River in the First Coast region of northeast Florida, about 25 miles (40 km) south of the Georgia state line and 340 miles (550 km) north of Miami. The Jacksonville Beaches communities are along the adjacent Atlantic coast. The area was originally inhabited by the Timucua people, and in 1564 was the site of the French colony of Fort Caroline, one of the earliest European settlements in what is now the continental United States. Under British rule, settlement grew at the narrow point in the river where cattle crossed, known as Wacca Pilatka to the Seminole and the Cow Ford to the British. A platted town was established there in 1822, a year after the United States gained Florida from Spain; it was named after Andrew Jackson, the first military governor of the Florida Territory and seventh President of the United States.
Harbor improvements since the late 19th century have made Jacksonville a major military and civilian deep-water port. Its riverine location facilitates Naval Station Mayport, Naval Air Station Jacksonville, the U.S. Marine Corps Blount Island Command, and the Port of Jacksonville, Florida's third largest seaport. Jacksonville's military bases and the nearby Naval Submarine Base Kings Bay form the third largest military presence in the United States. Significant factors in the local economy include services such as banking, insurance, healthcare and logistics. As with much of Florida, tourism is also important to the Jacksonville area, particularly tourism related to golf. People from Jacksonville may be called "Jacksonvillians" or "Jaxsons" (also spelled "Jaxons").
The area of the modern city of Jacksonville has been inhabited for thousands of years. On Black Hammock Island in the national Timucuan Ecological and Historic Preserve, a University of North Florida team discovered some of the oldest remnants of pottery in the United States, dating to 2500 BC. In the 16th century, the beginning of the historical era, the region was inhabited by the Mocama, a coastal subgroup of the Timucua people. At the time of contact with Europeans, all Mocama villages in present-day Jacksonville were part of the powerful chiefdom known as the Saturiwa, centered around the mouth of the St. Johns River. One early map shows a village called Ossachite at the site of what is now downtown Jacksonville; this may be the earliest recorded name for that area.
French Huguenot explorer Jean Ribault charted the St. Johns River in 1562, calling it the River of May because that was the month of his discovery. Ribault erected a stone column at his landing site near the river's mouth, claiming the newly discovered land for France. In 1564, René Goulaine de Laudonnière established the first European settlement, Fort Caroline, on the St. Johns near the main village of the Saturiwa. Philip II of Spain ordered Pedro Menéndez de Avilés to protect the interest of Spain by attacking the French presence at Fort Caroline. On September 20, 1565, a Spanish force from the nearby Spanish settlement of St. Augustine attacked Fort Caroline, and killed nearly all the French soldiers defending it. The Spanish renamed the fort San Mateo, and following the ejection of the French, St. Augustine's position as the most important settlement in Florida was solidified. The location of Fort Caroline is subject to debate but a reconstruction of the fort was established on the St. Johns River in 1964.
Spain ceded Florida to the British in 1763 after the French and Indian War, and the British soon constructed the King's Road connecting St. Augustine to Georgia. The road crossed the St. Johns River at a narrow point, which the Seminole called Wacca Pilatka and the British called the Cow Ford; these names ostensibly reflect the fact that cattle were brought across the river there. The British introduced the cultivation of sugar cane, indigo and fruits, as well the export of lumber. As a result, the northeastern Florida area prospered economically more than it had under the Spanish. Britain ceded control of the territory to Spain in 1783, after being defeated in the American Revolutionary War, and the settlement at the Cow Ford continued to grow.