I would assume that James Hoy and Margaret (Cavanaugh) Thomas met in Defiance County, Ohio since they both lived and married there. Margaret was married to her first husband Nicholas Thomas in 1875 in Defiance County. I do know she had 2 known children Elizabeth and Vincent (Vinnie) from her first marriage but i do not know what happened to them before or after she married James M Hoy.
The Hoy family migrated to Defiance County, Oh in about 1845 from Wayne County, Ohio. They are suppose to been from somewhere in Pennsylvania but i am not quite sure where. I have a couple sources pointing in the direction of Gettysburg, Pennsylvania (Adams County) but no concrete proof as of yet.
If you have any further questions, i will do my best to try to help. I been researching this family for about 6 years now.