Luis de Onís

Luis de Onís was a Spanish diplomat and military officer in the early 19th century. He is best known for negotiating the 1819 Adams-Onís Treaty, which settled territorial disputes between Spain and the United States. This treaty led Spain to cede Florida to the U.S. and defined the western boundary of the Louisiana Purchase. De Onís’s diplomatic skills helped improve relations between the two countries and shaped North American borders, playing a key role in the peaceful transfer of these territories. He contributed to Spain's diplomatic efforts in the New World during a period of significant geopolitical change.