Couple things. The name may also have been Johann Frederick on Baptismal records, as everyone in our family began with Johann in those days. Second, I've been told that German ports had ships that went only to other European ports. In those days, people went to England first to get on the big sailing ships that could cross the Atlantic. Germany didn't get into transatlantic shipping until steamships came on the scene, I have heard. That is why, for instance, the German shipping lines "New York" docks were actually in New Jersey, on the other side of the harbor --- the Dutch and English had filled the New York side before the Germans got into the business.