A negative search for what? And what searching have you done? If a census.... what specific year? Did you search by address? What Name? And Philadelphia changed boundaries several times..... so you can see your request, even if the domain of the federal authorities, has too many assumptions for anyone to issue such a letter. No time period, no federal documents including census and possibly immigration, no voting records, no marriage or birth records, etc.
A negative search for what? And what searching have you done? If a census.... what specific year? Did you search by address? What Name? And Philadelphia changed boundaries several times..... so you can see your request, even if the domain of the federal authorities, has too many assumptions for anyone to issue such a letter. No time period, no federal documents including census and possibly immigration, no voting records, no marriage or birth records, etc.
