Pedro Menéndez de Avilés founded St. Augustine, Florida, on September 8, 1565.
Menéndez was a Spanish admiral appointed Florida’s first governor. He established the settlement for Spain on the Atlantic coast, partly to protect shipping routes and challenge French activity in the region. The date was associated with the feast day of Saint Augustine of Hippo, because Menéndez’s fleet first sighted Florida on August 28.
St. Augustine is recognized as the oldest continuously inhabited European-established settlement in what is now the contiguous United States. That wording matters: San Juan, Puerto Rico, was founded earlier in 1521, and Native peoples lived throughout North America long before European settlement.
The city served as the capital of Spanish Florida for more than two centuries. Florida later passed to Britain, returned to Spain, and was ceded to the United States in 1819 before becoming a U.S. territory in 1821.