There is a good group of Glenns who have had DNA testing done. It has cleared up some mistaken paper trails for many of us. If you have a male Glenn in this line let me know and I can put you in touch with our Glenn who keeps up with this. Also, on a side note, you say that your James Glenn was born 1743 in Carlisle, Dauphin PA. Dauphin County didn't exist in 1743. It was formed from Lancaster County in 1785. Carlisle is a town in Cumberland County, which also didn't exist in 1743. It was across the Susquehanna River from Lancaster County and was formed when William Penn opened up settlements on the other side of the river in 1750. At that time Cumberland County was formed. So your James was probably born in Lancaster County in 1743.

I have a John Glenn b. 1771, likely in Cumberland County, as he appears in record there in the 1790s. He would fit with this James Glenn's family. We've had our line DNA tested, so if you can do the same, it might be very helpful.