Florida is a state located in the southeastern United States. Most of the state is a large peninsula with the Gulf of Mexico on its west and the Atlantic Ocean on its east. Most of the state has a humid subtropical climate, except for southern Florida, where the climate borders on tropical and the Florida Keys, which have a tropical climate. It was named by Juan Ponce de León, who landed in Saint Augustine on 2 April 1513, during Pascua Florida (Spanish for "Flowery Easter," referring to the Easter season). Florida's economy relies heavily on tourism. The capital is Tallahassee and the largest city is Jacksonville. The largest metropolitan area and a major cultural center of the state is Miami.

Archaeological finds indicate that Florida had been inhabited for thousands of years before any European settlements. Of the many indigenous peoples, the largest known were the Ais, the Apalachee, the Calusa, the Timucua and the Tocobago tribes. Juan Ponce de León, a Spanish conquistador, named Florida in honor of his discovery of the land on April 2, 1513, during Pascua Florida, a Spanish term for the Easter season. From that date forward, the land became known as "La Florida."

Over the following century, both the Spanish and French established settlements in Florida, with varying degrees of success. In 1559, Spanish Pensacola was established by Don Tristán de Luna y Arellano as the first European settlement in the continental United States, but it had become abandoned by 1561 and would not be reinhabited until the 1690s. French Huguenots founded Fort Caroline in modern-day Jacksonville in 1564, but this fort was conquered by forces from the new Spanish colony of Saint Augustine the following year. After Huguenot leader Jean Ribault had learned of the new Spanish threat, he launched an expedition to sack the Spanish settlement; en route, however, severe storms at sea waylaid the expedition, which consisted of most of the colony's men, allowing Saint Augustine founder Pedro Menéndez de Avilés time to march his men over land and conquer Fort Caroline. Most of the Huguenots were slaughtered, and Menéndez de Avilés marched south and captured the survivors of the wrecked French fleet, ordering all but a few Catholics executed beside a river subsequently called Matanzas (Spanish for 'killings'). Saint Augustine came to serve as the capitals of the British and Spanish colonies of East and West Florida, respectively.

The Spanish never had a firm hold on Florida, and maintained tenuous control over the region by converting the local tribes, briefly with Jesuits and later with Franciscan friars. The local leaders (caciques) demonstrated their loyalty to the Spanish by converting to Roman Catholicism and welcoming the Franciscan priests into their villages.

The area of Spanish Florida diminished with the establishment of English colonies to the north and French colonies to the west. The English weakened Spanish power in the area by supplying their Creek Indian allies with firearms and urging them to raid the Timucuan and Apalachee client-tribes of the Spanish. The English attacked Saint Augustine, burning the city and its cathedral to the ground several times, while the citizens hid behind the walls of the Castillo de San Marcos.

The Spanish, meanwhile, encouraged slaves to flee the English-held Carolinas and come to Florida, where they were converted to Roman Catholicism and given freedom. They settled in a buffer community north of Saint Augustine, called Gracie Real de Santa Teresa de Mose, the first completely black settlement in what would become the United States.

Great Britain gained control of Florida diplomatically in 1763 through the Peace of Paris (the Castillo de San Marcos surrendered for the first time, having never been taken militarily). Britain tried to develop Florida through the importation of immigrants for labor, including some from Minorca and Greece, but this project ultimately failed. Spain regained Florida after Britain's defeat by the American colonies and the subsequent Treaty of Versailles in 1783. Finally, in 1819, by terms of the Adams-Onís Treaty, Spain ceded Florida to the United States in exchange for the American renunciation of any claims on Texas and $5 million.

On March 3, 1845, Florida became the 27th state of the United States of America. On January 10, 1861, before the formal outbreak of the Civil War, Florida seceded from the Union; ten days later, the state became a founding member of the Confederate States of America. The war ended in 1865. On June 25, 1868, Florida's congressional representation was restored.

Until the mid-twentieth century, Florida was the least populous Southern state; however, the local climate, tempered by the growing availability of air conditioning, made the state a haven, and migration from the Rust Belt and the Northeast sharply increased the population. Economic prosperity combined with Florida's sudden elevation in profile led to the Florida land boom of the 1920s, which brought a brief period of intense land development before the Great Depression brought it all to a halt. Florida's economy would not fully recover until World War II. Today, with an estimated population over 18 million, Florida is the most populous state in the Southeastern United States, the second most populous state in the South behind Texas, and the fourth most populous in the United States.