Hi Jerome
I know the Carrowkeel,Ballisodare area well as I was born in the adjoining townland of Kilmacowen. My father Joseph SCANLON was born in Carrowkeel.I live in Sligo County.I have cousins living on the family farm of Carrowkeel and my sister lives in the family home in Kilmacowen
I have an interest in your Nelson family as I think some of my Scanlon ancestors in Carrowkeel were married to Nelsons.I found on Church Records , a record of birth for Henry Nelson (1860)and John Nelson(?) from Carrowkeel. The Parents were Henry Nelson and Catherine SCANLON.I also found a marriage record for a John Nelson from Carrowkeel who married a Joanna Tracy in 1876.
There are at least 5 townlands in Co.Sligo called Carrowkeel
The one your Nelson ancestors come from is Townland of CARROWKEEL in the Civil /Electoral District of KILMACOWEN in the Barony of CARBURY. The Church records were in ST John's/Calry ,Diocese of Elphin (Now the Cathedral) in Sligo town. The POSTAL address was and still is >>> CARROWKEEL, BALLISODARE,Co.Sligo.
Carrowkeel is 3 miles from Sligo Town and from Ballisodare.The cemetery for Carrowkeel is Kilmacowen. There are 3 Nelson graves in Kilmacowen Cemetery.
Grave 1 > Henry Nelson and wife Katie.(no dates)
Grave 2> John F??? (illegible) and his wife Mary Nelson died 1822
Grave 3 > Elizabeth Nelson (nee Scanlon) who died 1813 aged 41
I can get photographs of these graves for you.
Unfortunately the Church records for St Johns/Calry are not available for the years befor 1858

Regards
Rosaleen Scanlon
Web site
http://underbenbulben.ie/home.aspx