I would highly recommend getting to the bottom of your family history mystery by using one of the many DNA kits now available at very reasonable prices. I used AncestryDNA and 23andme for autosomal testing. My mother and sister also tested (as have many other family members!). I also did my MtDNA with FamilytreeDNA and my nephew did Y-DNA, also with FamilytreeDNA. This has given me a complete picture of my heritage and also allowed me to connect to many cousins around the world. I have uploaded my autosomal results to GEDmatch.com, MyHeritage and LivingDNA, so I can reach as many cousins as possible.

AncestryDNA

MyHeritage

23andme