Questions About Fortin Family

Seeking Fortin, my grandfather

I'm doing a family tree. As part of doing this, I'm trying to trace the ancestors of my maternal grandfather, Lawrence Fortin. The problem is that not only did he die before I was born (in the 40s), as it turns out he was adopted by the Fortin family. The question is, where on earth do I begin in finding records on Lawrence Fortin and who his biological family was? Note: unfortunately, I'm starting out knowing nothing about him, since my late grandmother kicked him out in the late 40s and disliked talking about him. My mom doesn't remember him. All I can tell you is that they lived in Worcester, MA during their marriage and were probably married there. By the way, in case this helps sleuths out there, he allegedly died at age 28 (again, late 40s), of cirrhosis of the liver (you see why grandma booted him), in a hospital in Rhode Island. Also, at the risk of being obvious, from my other geneological studies I've learned that many, many Fortins emigrated from Q