Spanish Florida refers to the territory in North America that was claimed by Spain from the 16th century until the early 19th century. It included the present-day state of Florida and parts of Alabama, Mississippi, and Louisiana. The Spanish established several settlements, with St. Augustine being the oldest continuously inhabited European-established settlement in the continental United States, founded in 1565. During its time as a Spanish colony, Florida served as a strategic location for trade and military operations. The region was home to various Indigenous peoples, including the Timucua and Seminole tribes. In 1821, Spain ceded Florida to the United States through the Adams-Onís Treaty.