Rick,

The information can be found at the Johnson/Johnston/Johnstone DNA surname project through FamilyTreeDNA. I am a descendant of Sill Johnson (ca. 1695/1701-1763) of Johnston County, NC via two of his sons, Henry Johnson (ca. 1730/40-1807) of Johnston County, NC and Benjamin Johnson (ca. 1750/55-ca. 1825) of Cumberland (now Harnett) County, NC. My second cousin once-removed, who is a direct male descendant of Sill Johnson via son Benjamin, was DNA tested for this line. The Sill Johnson line is haplotype I2a, and is part of the "Burr Oak" family group at the Johnson/Johnston DNA project. The President Andrew Johnson line is haplotype I2b, and is part of the "Scarlet Oak" family group.

http://freepages.genealogy.rootsweb.ancestry.com/~hjohnson/N...


Hope this helps.