Heinrich HEISER served aboard the ship Germantown as a Marine from late 1847 until 1851 , sailing from Norfolk to the Gulf during the Mexican War. He had enlisted in Philadelphia. When the war was over, he stayed aboard, sailing/protecting the southern and eastern coast of US and in the Caribbean until 1851 when he was discharged at the Marine Barracks of the Navy Shipyard in Brooklyn, NY. This I determined from his pension file and the Dictionary of Fighting Ships which documents the itinerary of the Germantown. My question: were men accounted for somewhere who were serving aboard a ship during a census year?