When did they rule out 1st cousins? A set of my great-grandparents had to go from Illinois to Kentucky to get hitched back in the 20’s because they were 1st cousins—the relationship was no problem, but as one of them was a bit darker than the other, there was some concern about inter-racial marriage.
About half the states allow first cousins to marry. Children born to first cousins have about twice the risk of a genetically transmitted birth defect compared to children of more distantly related parents.