Marconi Beach is part of the Cape Cod National Seashore in Wellfleet, Massachusetts. The beach is named for Italian inventor Guglielmo Marconi. In 1903, the first transatlantic wireless communication originating in the United States was successfully transmitted from nearby Marconi Station; a message from U.S. President Theodore Roosevelt to King Edward VII of the United Kingdom. The beach was also used by the former Camp Wellfleet for artillery and rocket testing.