Unfortunately, the Alexanders, like most Scots-Irish settlers were rather thrifty with family names, using and re-using them---often within the same generation.(Frustration!) I have a James Alexander born circa 1725-35 (a son of Moses and Mary) whose wife's name isn't known, but among the children were (probably): James, Jr abt 1754, Matthew abt 1757, William, Ebenezer and Margaret. There seems to be substantial documentation for the James Jr and Matthew. There may have been other children. Tradition has it this family was originally in Rowan, but when the border dispute between the Carolinas was settled, their farm wound up in Spartanburg County SC.The time frame is about right, but don't know if this could be same James you are looking for.