Sons of Thomas McMillan & Virgina Hutchison McMillan

Hi. I am a female, age 57, who lives in the counrty in a small town up north in Mi. I am doing a family tree on the McMillans from Bridgeville Pennsylvania and all connections of surnames to this family.The Bridgeville McMillans started with Andrew McMillan who came over from Ireland,he was murdered in Allegheny County while coming home from a cattle sale. His son Thomas McMillan went back with his mother to Ireland after his fathers death ,but came back to the Untied States sometime in the early 1800's. His father Andrew had a farm and tract of land in Lawrenceville, Pennsylvania before his death and Thomas had a tract of land in Bridgeville, Pennsylvania.Anyone has any info on this family please notify me.