First thank you for your reply and help.Yes, I have been thru both birth certificates and death certificates.I will try to briefly to explain my problem.My paternal grandfather was born in Ireland in February(?) 1876.In June of 1901 in Waverly Iowa he(Dennis Sullivan) married my grandmother (Bridget Sullivan) , yes, same last name. So sometime between 1876 and 1901 he emigrated to the U.S.. He and his family ,Father(Florence Sullivan) and mother Mary Shea(?) settled in Joliet, Il. In 1906 @ age 29 Dennis died in Waverly. According to the Obits in the Waverly papers a sister and a brother came from Joliet to attend the funeral. No names of the brother or sister given.In searching through records (census, directories, etc) I have located a Florence and Mary Sullivan who lived in Joliet at the time and are buried together in Mt. Olivet cemetery in Joliet.However thier Obits do not list a son Dennis and therin lies my dilemna.I have no concrete proof that the Florence and Mary buried in Joliet are the parents of My Dennis and hence my Great Grandparents.