Adams-Onís Treaty signed aka Florida Purchase

A treaty between the United States and Spain in which Spain ceded Florida to the US and defined the border between New Spain (Mexico) and the US. The US at the time was very concerned with crushing Seminole and Maroon communities who offered a haven to runaway slaves and conducted raids into Georgia. The First Seminole War from 1817-18 had concluded just before this and Spain was not willing or able to defend their territory from the American Army incursions due to uprisings and movements for independence from Spanish colonialism in their other colonies.