The United States has been invaded only twice by enemy military forces since the War of 1812. Both invasions were by small parties of German saboteurs during World War II. On June 13, 1942, four men came ashore by boat from a submarine at Amagansett, Long Island, New York. Four days later, four other Germans landed along the isolated beach some four miles south of Ponte Vedra, a luxurious resort on the upper east coast of Florida near Jacksonville. These German invasions were a part of the Abwehr’s Operation Pastorius.
Prior, Leon O.
"Nazi Invasion of Florida!,"
Florida Historical Quarterly: Vol. 49
, Article 4.
Available at: https://stars.library.ucf.edu/fhq/vol49/iss2/4