Hello Alice, Because John and Sarah were born in Pennsylvania and were born there before the 1841 UK Census, both their parents would also have been living in America and would not be recorded on any Census in the UK. Have you got details of their marriage which would give you the details at least of the fathers of both John and Sarah, our UK Civil Marriages Registrations started in July 1837, have you the same type records in the USA. Best of Luck Regards Barbara