What did the Adams-Onis Treaty do?

The Adams–Onís Treaty, also known as the Transcontinental Treaty, was a significant diplomatic agreement between the United States and Spain in 1819. Here are its key provisions:

1. Cession of Florida: The treaty ceded Florida to the United States. Spain, burdened by the territory and unable to send settlers or maintain garrisons, decided to transfer Florida to the U.S.

2. Boundary Definition: It defined the boundary between the U.S. and Mexico (New Spain). This settled a longstanding border dispute between the two countries.

3. Territorial Exchange: In exchange for Florida, the U.S. agreed to:
Pay residents’ claims against the Spanish government, totaling up to $5 million Spanish dollars.
Relinquish U.S. claims on parts of Spanish Texas west of the Sabine River and other Spanish areas, as per the terms of the Louisiana Purchase.

4. Rocky Mountains to the Pacific: The treaty established the U.S. boundary and claims from the Rocky Mountains westward to the Pacific Ocean.

5. Triumph of American Diplomacy: The Adams–Onís Treaty was considered a diplomatic triumph for the U.S. It came during the successful Spanish American wars of independence against Spain.

6. Short Duration: Remarkably, the treaty remained in effect for only 183 days, from February 22, 1821, to August 24, 1821. During this time, Spanish military officials signed the Treaty of Córdoba, acknowledging Mexico’s independence.

7. Border Recognition: The Treaty of Limits between Mexico and the United States, signed in 1828, recognized the border defined by the Adams–Onís Treaty as the boundary between the two nations1234.

In summary, the Adams–Onís Treaty resolved territorial disputes and shaped the U.S.–Mexico border, marking a pivotal moment in American diplomacy.