Hi Robert,I am sorry to hear about the death of your grandfather.
I hope that you found out the name of both his parents and the names of both your grandmother's parents.The more information you have the better it is getting help.
I live in Oregon and so I went to http://www.acgs.org/http://www.acgs.org/ This is a American/Canadian Genealogy Society in Manchester, NH.There are several around the east coast.There is a fee for the research.The fee is less if you are a member.I found it worthwhile to join.
Give them all the information that you have (hopefully your parents and grandmother can help).If the society locates your grandparents with whatever information you give them, they will then trace every generation of ancestors from your grandfather to the pioneer Jean Riou/Rioux. They have most of the USA church records.
The membership fee may be around $30 and another $35 for a direct line Rioux research to our pioneer ancestor.If you are not a member the direct line research will be about $55.It was worht my being a member.I had them do 6 of my great grandparents lines
Somewhere you will join one of my ancestors and I will be able to give you more information on their spouces.
Also if you find out the parents of your grandfather and their wedding information, let me know. I may be able to post a query at CGFA a French web site.