How did the US gain land of Florida?

The United States acquired the Florida territory through the Adams–Onís Treaty of 1819. This treaty was signed between the United States and Spain and resolved various territorial disputes between the two countries. As part of the agreement, Spain ceded East Florida and West Florida to the United States, giving the US control of the entire Florida peninsula. In exchange, the United States assumed claims of American citizens against the Spanish government for damages sustained between 1792 and 1802, up to the amount of $5 million. The treaty was ratified in 1821, officially transferring the Florida territory to the United States.