I have a letter addressed to John H Piatt, esq. dated Oct 25,1812 from Brig Gen James Winchester. At that time John was in St. Mary's, Oh., but he wasn't there in the 1820 census. One other clue, John was concerned with a herd of his hogs that the Gen had appropriated for his army at Fort Winchester (I think it was a temporary name for Fort Defiance but not sure. Email me if John is in your family. Click on my name for my Email address.