How did the united states obtained the purchase of floridia to extand its frontiers to the pacific ocean

The Adams–Onís Treaty of 1819, also known as the Transcontinental Treaty, the Florida Purchase Treaty, or the Florida Treaty, was a treaty between the United States and Spain in 1819 that ceded Florida to the U.S. and defined the boundary between the U.S. and New Spain.

i think it is the byzantine empire

b]to spread the message of black power