The US Navy achieved the first transatlantic flight eight years before Charles Lindbergh became world famous for crossing the Atlantic nonstop and alone. Three Curtiss flying boats, each with a crew of six, were involved: NC-1, NC-3, and NC-4. The Navy wanted to prove the capability of the airplane as a transoceanic weapon and technology.
The five-leg flight began on May 8, 1919, at the naval air station at Rockaway Beach, New York. It followed a route to Nova Scotia; Newfoundland; the Azores in the middle of the Atlantic; Lisbon, Portugal; and Portsmouth, England. Only NC-4, commanded by Albert C. Read, flew the whole way. The entire trip took 24 days.
Conceived during the First World War, the NC class of flying boats, popularly known as "Nancy Boats," was intended to meet a U.S. Navy requirement for extended range aircraft for anti-submarine patrol. An important design consideration of the NC class held that these flying boats be capable of flying under their own power from the continental United States to the European war zone because shipping space was in short supply during this period in 1917. The German U-boat offensive at the time was sinking close to one million tons of Allied shipping every month.