The first European known to have encountered Florida was Juan Ponce de León, who claimed the land as a possession of Spain in 1513.

St. Augustine, the oldest continually inhabited European settlement in the continental U.S., was founded on the northeast coast of Florida in 1565.

Florida continued to remain a Spanish possession until the end of the Seven Years' War, when Spain ceded it to the Kingdom of Great Britain in exchange for the release of Havana.

These disputes were ostensibly solved in 1795 by the Treaty of San Lorenzo, which, among other things, solidified the boundary of Florida and Georgia along the 31st parallel.

[3]: xviii–xix In 1812, United States forces and Georgia "patriots" under General George Mathews unsuccessfully invaded Florida to protect American interests.

President James Madison withdrew his support, and the Spanish authorities were promised a speedy exit of the American troops.

[4]: 39 The Spanish government offered runaway slaves freedom if they converted to Catholicism and agreed to a term of military service.

They lived in a semi-feudal system; the Seminoles gave the Blacks protection, while the former slaves, who knew how to farm, shared crops with the natives.

[4]: 18–22 In 1818, after years of additional conflicts involving natives, fugitive slaves, and settlers, General Andrew Jackson wrote to President James Monroe, who had been inaugurated in March 1817, informing him that he was invading Florida.

[note 1] Under Article 15, Spanish goods received exclusive most favored nation tariff privileges in the ports at Pensacola and St. Augustine for twelve years.

[195 U.S. 138, 142] 'This treaty is the law of the land, and admits the inhabitants of Florida to the enjoyment of the privileges, rights, and immunities of the citizens of the United States.

[9] Andrew Jackson served as the federal military commissioner with the powers of governor of the newly acquired territory, from March 10 through December 1821.

[10] William Pope Duval became the first official governor of the Florida Territory and soon afterward the capital was established at Tallahassee, but only after removing a Seminole tribe from the land.

On May 28, 1830, Congress passed the Indian Removal Act requiring all Native Americans to move west of the Mississippi River.

[4]: 87  The Act itself did not mean much to Florida, but it laid the framework for the Treaty of Payne's Landing, which was signed by a council of Seminole chiefs on May 9, 1832, and ratified in 1834.

[14][15] On December 18, 1821, the Alabama state legislature passed a resolution asking the U.S. Congress to annex the portion of Florida west of the Apalachicola River, but nothing materialized from the proposal.

On April 22, 1840, Congress received a petition from several hundred backers in St. Augustine asking to split the territory in two, with the Suwanee River being the dividing line between East and West Florida.

However no results were returned for five counties (Mosquito, Nassau, Columbia, Hamilton and Duval) and no official documents of the census are known to survive with all information coming from newspapers reporting on it.