The evidence is almost definitely not the letter with the "cousin" statement; that letter was not available to my great-aunt Bernice Howard Fairall. She does refer to a record of a John Fairall who served in the American Revolutionary War - but nothing connecting William H. Fairall to Erasmus Fairall. I don't know where she got the date of birth and death for Erasmus, either. I think probate records and wills are the place to search, but unfortunately it could be any county in the states of Ohio and Maryland. It is probably Garrett County or Baltimore City/County if Maryland. I have no idea which county it could possibly be in Ohio... a mystery to further investigate!