The Adams-Onis Treaty Is Concluded
In the agreement, the U.S. received the territorial rights to Spanish Florida (British East and West Florida) in exchange for payments by the United States of residents' claims against the Spanish government up to a total of $5,000,000 and relinquishing its own claims on parts of Texas west of the Sabine River and other Spanish areas. The treaty was concluded on February 22, 1819, in Washington, D.C., ratifications were exchanged, and the treaty was proclaimed on February 22, 1821. The U.S. commission established to adjudicate claims considered some 1800 claims and agreed that they were worth $5,454,545.13. Since the treaty limited the payment of claims to $5 million, the commission reduced the amount paid out proportionately by 8 1/3 per cent.
The Adams-Onís Treaty settled the dispute by attempting to draw clearer borders, roughly granting Florida and Louisiana to the U.S. while giving to Spain everything west of Louisiana from Texas to California. The new boundary was to be the Sabine River north from the Gulf of Mexico to the 32nd parallel north, then due north to the Red River, west along the Red River to the 100th meridian, due north to the Arkansas, west to its headwaters, north to the 42nd parallel north, and finally west along the parallel to the Pacific Ocean.
Wikipedia: Adams-Onis Treaty