It is interesting to note that the birth State that had the majority of African American people with the surname Brannon (or variants) was Virginia.
Born in Africa 1
Born in Alabama 121 men, wome and children with the surname Brannon/Brandon/Branine/Brannen/Brannan
Born in Arizona none
Born as Arkansas 24 men, women and children
Born in Colorado none
Born in South Carolina 80 men, women and children with the surnames as above
Born in North Carolina 146 men women and children with the surnames as above
Born in Dakota, North and South none
Born in Florida 33
Born in Georgia 192 men, women and children
Born in Illinois 12 men, women and children
Born in Indiana 2 man and child
Born in Iowa 2 man and boy
Born in Kentucky 58 men, women and children
Born in Louisiana 50 men, women and children
Born in Maine none
Born in Michigan 4
Born in Mississippi 87 men, women and children
Born in Missouri 11 men, women and children
Born in Montana none
Born in Nebraska 1 man
Born in Nevada none
Born in Ohio 13 men, women and children
Born in Oregon none
Born in Pennsylvania 5 men, women and children
Born in New York 13 men, women and children
Born in Tennessee 60
Born in Texas 23 men, women and children
Born in Virginia 363 men, women and children
Born in West Virginia 1 boy
Born in Wisconsin none
Born in Wyoming none
Source U. S. Federal Census ancestry.com