What country gave control of Florida to US with a treaty written in 1819?

Spain ceded control of Florida to the United States through the Adams-Onís Treaty, signed in 1819. The treaty was named after U.S. Secretary of State John Quincy Adams and Spanish Minister Luis de Onís. It officially transferred Florida to the U.S. and resolved territorial disputes between the two nations. The treaty was ratified in 1821, marking the formal acquisition of Florida by the United States.