The first commercial passenger trans-Atlantic service was by Pan Am in 1939 between NYC & this French port
In 1937 Pan Am turned to Britain and France to begin seaplane service between 
... Bay of Exploits in Newfoundland from Port Washington, New York, ... first steps 
toward commercial transatlantic flights in heavier-than-air craft... [DOC] [TLE] Conquering the Atlantic by Don Cooper: Read the PDF [PAR] Dixie Clipper" Crossing the Atlantic June 29, 1939 ...