Florida comprises, more or less, OTL US state of Florida east of the Appalachian Mountains.
The Republic of Florida was formerly a Spanish colony comprising the Florida peninsula and an undefined territory north of it. It was in constant competition with the English (who were founding colonies in the North), shortening the "undefined territory" the Spanish laid claims to, until the British received all of Florida in the French and Indian War of 1763.
Florida was returned to Spain in 1783, after the American War of Independence, but immediately began to suffer from settlements, incursions and escaped slaves from Georgia.
Georgia invaded Florida in 1806. However, Spanish naval superiority and St Augustine fortifications proved essentials for protecting East Florida and the peninsula. Greater manpower allowed Georgians to control West Florida and the territories between the Perdido and Mississippi Rivers.
In the Mobile Treaty of 1808, Spain ceded the territories between the Appalachicola and the Pearl Rivers (south of the 31st parallel) and all territories East of the Mississippi (north of 31st parallel) to Georgia. On the other hand Georgia recongized Spanish authority over East Florida and the peninsula, recognizing current borders of the Republic.
The Spanish succession crisis of 1863 triggered an independentist movement in the Americas. Florida declared her independence in 1864, almost uncontested (by this time, the Spanish Armada was completely out-competed by the Royal Navy and Spanish force projection was close to nil).
Spain recognized the independence of the former colonies in 1876.
The Spanish authorities tried to discourage slave-based economy in Florida after the Georgian invasion, but given the importance of slaves in Cuba, slavery was not forbidden.
By the Floridan independence, slave was mostly restricted to domestic and personal service. The constitution of the new Republic ban slavery.
Florida is composed, mostly, by the peninsula of the same name.
The Republic of Florida borders: North: Georgia. West: Gulf of Mexico. South: Florida Strait. East: Atlantic Ocean.
The Republic of Florida is a unitary republic divided in communes (comunas, sing. comuna), grouped in three regions: North, Central and South.