Final answer:
The Adams-Onís Treaty of 1819 resulted in Spain ceding Florida to the United States. The treaty also established the U.S.-Mexico boundary line at the Sabine River and involved the U.S. relinquishing claims to Texas and Spain to Oregon.
Step-by-step explanation:
The Adams-Onís Treaty of 1819
In the Adams-Onís Treaty, signed in 1819, Spain ceded the territory of Florida to the United States. This agreement was significant because it not only granted the U.S. control over Florida, but it also established the boundary between U.S. territory and New Spain.
The United States paid $5 million to Spain and renounced its claims to Texas, while Spain relinquished its claims to Oregon. The acquisition of Florida was a strategic move by the U.S. as it eliminated a haven for runaway slaves and also resolved ongoing conflicts with the Creek and Seminole tribes.
General Andrew Jackson played an instrumental role in bringing Spain back to the negotiating table after he pursued Creek and Seminole raiders into Spanish Florida. This act of aggression, rather than receiving condemnation, was leveraged by U.S. Secretary of State John Quincy Adams to convince Spain to cede Florida.
Additionally, the boundary was drawn at the Sabine River, marking the separation between the United States and Mexico.
Therefore, in a multiple-choice question, Florida would be the correct answer (Option A) to the question of which territory the United States gained from Spain as a result of the Adams-Onís Treaty.