Adams–Onís Treaty
The treaty was signed in Washington, DC on February 22, 1819. It was ratified in Madrid, Spain on October 24, 1820. The treaty actually went into effect on February 22, 1821. Madrid decided to cede the territory of Florida to the United States. This was in exchange for settling the boundary dispute along the Sabine River in Texas. The treaty established the boundary of U.S. territory. It recognized the claims of the United States through the Rocky Mountains and west to the Pacific Ocean. In exchange the U.S. paid residents' claims against the Spanish government up to a total of $5,000,000. The United States also gave up its claims on parts of Spanish Texas west of the Sabine River and other Spanish areas, under the agreements in the Louisiana Purchase. Adams-Onis was a key event in determining the U.S.-Mexico border.