Why Did the U.S. Negotiate the Purchase of Florida?

The Adams–Onís Treaty (1819) (ratified 1821) transferred Spanish Florida to the U.S. Key motivations:

1. Spanish weakness: Spain couldn't effectively govern or defend Florida (seminole raids, runaway slaves, filibusters).
2. U.S. expansionism: Desire for territorial continuity, Gulf access, and elimination of a foreign foothold.
3. Border clarity: Settled the ambiguous Louisiana Purchase western boundary (Sabine River).
4. Diplomatic leverage: Spain sought U.S. support against Latin American independence movements; U.S. gave up claims to Texas (temporarily) in exchange.
5. No cash payment: U.S. assumed $5M in American citizens' claims against Spain instead of paying Spain directly.

The treaty also defined the U.S.–New Spain (later Mexico) boundary to the Pacific.