The present-day U.S. state named by Juan Ponce de León in 1513 was Florida.
Ponce de León led a Spanish expedition that left Puerto Rico in March 1513. The explorers sighted land during the Easter season and called it La Florida. The name is commonly connected with Pascua Florida, the Spanish Easter season, and may also reflect the region’s abundant vegetation. Ponce claimed the land for the Spanish Crown and explored parts of its Atlantic and Gulf coasts.
Florida was not necessarily the first European sighting of the peninsula, since earlier Spanish voyages may have reached it. Ponce de León is remembered because his expedition was the first officially documented Spanish expedition to Florida and helped establish the name on European maps.
A popular story says Ponce was searching for the Fountain of Youth, but no contemporary evidence shows that this was his purpose. His 1512 royal contract instead authorized him to search for islands and lands north of the Caribbean. Virginia, Georgia, and California were named or colonized in different contexts and were not the answer to this 1513 question.