Augustine and Pensacola were respectively made the capitals of East Florida and West Florida. Under the Treaty of Paris (1783), Florida was returned to Spain. Many colonists in Florida abandoned the region and moved to British possessions in the West Indies. Spain's hold over Florida, however, was extremely tenuous. Boundary disputes developed with the United States (see West Florida Controversy). In the War of 1812, Pensacola served as a British base until captured (1814) by U.S. General Andrew Jackson. In 1819, after years of diplomatic wrangling, Spain reluctantly signed the Adams-Onis treaty ceding Florida to the United States in return for U.S. assumption of 5 million in damages claimed by U.S. citizens against Spain. Official U.S. occupation took place in 1821, and Andrew Jackson was appointed military governor. Florida, with its present boundaries, was organized as a territory in 1822, and William P. Duval became its first territorial governor. Florida was admitted to the Union in 1845 as a slaveholding state.
The U.S. Territory of Missouri was set up in 1812, but settlement was slow even after the War of 1812. The coming of the steamboat increased traff