Sorry, I was one generation off. Your Samuel McKeen (Apr. 1777-1845) married to Sarah Logan (June 8, 1785-April 12,1861) is the Grandfather of my Andrew Logan McKeen.
My Andrew was born May 29, 1804 in Aspen, Nova Scotia, and is the son of John Logan McKeen (b. 1804) and Margaret Ann Pringle. The above mentioned John Logan McKeen is a brother of William Logan McKeen.
The family of Samuel McKeen (1775-1845) became known as the "Logan McKeen's" because of the frequent use of the Logan name.
I have photographs of many of the above monuments I believe if you are interested?