My husband's Grahams came from Lamar County, on the western boarder of Alabama. I believe your William Graham is his ancestor. Charles H. Graham (Oct 4, 1825 - March 14, 1912) was buried in Walnut Grove Cemetary in Lamar Co. with his wife Nancy. I think it was the LDS site that connected him with Selah and William Graham of Abbeville, SC. I am so excited to find the immigrant from Belfast! I assume they are Scots-Irish.