I cannot be of much help. The only Elam I have in my various family lines is Elam Alexander who was born in North Carolina, son of James Alexander & Betsey Ross. He lived briefly in Rutherford County, Tennessee along with a couple of his brothers. Then he moved to Bibb County, Georgia.
I have no knowledge of either NA or of tri-racial background for this family. I also have not found a connection to the Weeden/Weedin family.