Apalachicola River in the context of Chattahoochee River

The Floridas (Spanish: Las Floridas) was a region of the southeastern United States comprising the historical colonies of East Florida and West Florida. They were created when Great Britain obtained Florida in 1763 (see British Florida), and found it so awkward in geography that it split the territory in two. The borders of East and West Florida varied. In 1783, when Spain acquired West Florida and re-acquired East Florida from Great Britain through the Peace of Paris (1783), the eastern British boundary of West Florida was the Apalachicola River, but Spain in 1785 moved it eastward to the Suwannee River. The purpose was to transfer the military post at San Marcos de Apalachee (now St. Mark's) and the surrounding district from East Florida to West Florida. From 1810 to 1813, the United States extended piecemeal control over the part of West Florida that comprised the modern-day Gulf coasts of Alabama and Mississippi and the Florida Parishes of Louisiana. After the ratification of the Adams-Onis Treaty in 1821 the United States combined East Florida and what had been the remaining Spanish-controlled rump of West Florida into the territory that comprises modern-day Florida.

East Florida (Spanish: Florida Oriental) was a colony of Great Britain from 1763 to 1783 and a province of the Spanish Empire from 1783 to 1821. The British gained control over Spanish Florida in 1763 as part of the Treaty of Paris that ended the Seven Years' War. Deciding that the colony was too large to administer as a single unit, British officials divided Florida into two colonies separated by the Apalachicola River: the colony of East Florida, with its capital located in St. Augustine; and West Florida, with its capital located in Pensacola. East Florida was much larger and comprised the bulk of the former Spanish colony and most of the current state of Florida. It had also been the most populated region of Spanish Florida, but before control was transferred to Britain, most residents – including virtually everyone in St. Augustine – left the territory, with most migrating to Cuba.

Britain tried to attract settlers to the two Floridas without much success. The sparsely populated colonies were invited to send representatives to the Continental Congress but chose not to do so, and they remained loyal to Great Britain during the American Revolutionary War. However, as part of the 1783 treaty in which Britain officially recognized the independence of thirteen of its former colonies as the United States, it ceded both Floridas back to Spain, which maintained them as separate colonies while moving the boundary east to the Suwannee River.

West Florida (Spanish: Florida Occidental) was a region on the northern coast of the Gulf of Mexico that underwent several boundary and sovereignty changes during its history. Great Britain established West and East Florida in 1763 out of land acquired from France and Spain after the Seven Years' War. As its name suggests, it was formed out of the western part of former Spanish Florida (East Florida formed the eastern part, with the Apalachicola River as the border), along with land taken from French Louisiana. Pensacola became West Florida's capital. The colony included about two thirds of what is now the Florida panhandle, as well as parts of the modern U.S. states of Louisiana, Mississippi, and Alabama.

As the newly acquired territory was too large to govern from one administrative center, the British divided it into two new colonies separated by the Apalachicola River. British West Florida included the part of former Spanish Florida, which lay west of the Apalachicola, as well as parts of former French Louisiana. Its government was based in Pensacola. West Florida thus encompassed all territory between the Mississippi and Apalachicola Rivers, with a northern boundary which shifted several times over the subsequent years.

The Indigenous peoples of Florida lived in what is now known as Florida for more than 12,000 years before the time of first contact with Europeans. However, the indigenous Floridians living east of the Apalachicola River had largely died out by the early 18th century. Some Apalachees migrated to Louisiana, where their descendants now live; some were taken to Cuba and Mexico by the Spanish in the 18th century, and a few may have been absorbed into the Seminole and Miccosukee tribes.

The Florida panhandle (also known as West Florida and Northwest Florida) is the northwestern part of the U.S. state of Florida. It is a salient roughly 200 miles (320 km) long, bordered by Alabama on the west and north, Georgia on the north, and the Gulf of Mexico to the south. Its eastern boundary is arbitrarily defined. It is defined by its southern culture and rural demographics in contrast to urbanized central and southern Florida, as well as closer cultural links to Alabama and Georgia. Its major communities include Pensacola, Navarre, Destin, Panama City Beach, and Tallahassee.

As is the case with the other eight U.S. states that have panhandles, the geographic meaning of the term is inexact and elastic. References to the Florida panhandle always include the ten counties west of the Apalachicola River, a natural geographic boundary, which was the historic dividing line between the British colonies of West Florida and East Florida. These western counties also lie in the Central Time Zone (with the exception of Gulf County, which is divided between the Eastern and Central Time zones), while the rest of the state is in the Eastern Time Zone. References to the panhandle may also include some or all of eleven counties immediately east of the Apalachicola known as the Big Bend region, along the curve of Apalachee Bay.