S.C. Code Ann. § 20-1-10 – Persons who may contract matrimony

(A) All persons, except mentally incompetent persons and persons whose marriage is prohibited by this section, may lawfully contract matrimony.
(B) No man shall marry his mother, grandmother, daughter, granddaughter, stepmother, sister, grandfather's wife, son's wife, grandson's wife, wife's mother, wife's grandmother, wife's daughter, wife's granddaughter, brother's daughter, sister's daughter, father's sister, mother's sister, or another man.
(C) No woman shall marry her father, grandfather, son, grandson, stepfather, brother, grandmother's husband, daughter's husband, granddaughter's husband, husband's father, husband's grandfather, husband's son, husband's grandson, brother's son, sister's son, father's brother, mother's brother, or another woman.
Property rights arising from relationship of couple cohabiting without marriage. 69 ALR5th 219.
Marriage between persons of the same sex. 81 ALR 5th 1.