How did the Adams-Onis Treaty of 1819 affect Louisiana? It returned Louisiana to Spanish control, recognizing and honoring an earlier treaty with the French. It allowed the French to occupy Louisiana for ten years after its sale before control would transfer to the United States. It stated that Louisiana was jointly controlled and administered by Spain, France, and the United States. It defined the western boundary of Louisiana, separating the United States and Spanish territory.

Under the Onís-Adams Treaty of 1819 (also called the Transcontinental Treaty and ratified in 1821) the United States and Spain defined the western limits of the Louisiana Purchase and Spain surrendered its claims to the Pacific Northwest. In return, the United States recognized Spanish sovereignty over Texas.

The Adams-Onis Treaty of 1819 defined the western boundary of Louisiana, separating the United States and Spanish territory.

Explanation:

The Adams-Onis Treaty of 1819 is a historic treaty between the United States and Spain that defined the border between the two nations, then disputed, in North America. This treaty was the result of growing tensions between the two countries over territorial rights during a period of weak Spanish power on the American continent. In addition to the cession of Florida, the treaty established a boundary on a disputed area along the Sabine River in Texas and firmly established it between American territory and New Spain to the Rockies and the Pacific Ocean, along the 42nd north parallel. In addition, by this treaty Spain recognized American sovereignty over Louisiana, which was purchased from France.