Try http://www.archives.gov/genealogy/http://www.archives.gov/genealogy/. Under "Most Requested", click "census records". Then click "Ancestry Library". They give free access to the census records. If you can't find them under their real name, try different spellings or unclick "Exact". They have the states of where they were born in and where their parents were born on the original record. Sometimes they also have months on the original record. Don't go just by one record though, because sometimes they get it wrong on one but right on the others. I hope this helps.