Over forty years ago, I positively identified the progenitor of my maternal grandmother's family (Rees) as one John Rhys. He was definitely of Welsh descent. I know he was married to Margaret Jones (David & Elizabeth Davies) on 19 Apr 1773 in St. James Episcopal Church, Lancaster, Lancaster County, Pennsylvania. He served as a Captain in the Revolutionary War, commanding a company in the 2nd Pennsylvania Battalion, 3rd Pennsylvania Regiment, under Col. Arthur St. Clair, which took part in the ill-fated expedition against General Burgoyne's English troops at Québec in the spring of 1776.
John died in Aug 1787 in Morgantown, Berks County, Pennsylvania, and was buried there. Margaret later remarried to David Morgan and lived until 30 Dec 1830.
Any help would be most appreciated. This is my 40-year brick wall and it needs to come down.