Marriage between first cousins is only unconditionally legal in 19 U.S.states and the District of Columbia. Marriage between cousins under certain circumstances is legal in six states, but it is illegal in the remaining 25 states, according to the National Conference of State Legislatures.
The NCSL states that cousins can legally marry with no restrictions in Alabama, Alaska, California, Colorado, Florida, Georgia, Hawaii, Maryland, Massachusetts, New Jersey, New Mexico, New York, Rhode Island, South Carolina, Tennessee, Vermont and Virginia.
First cousins can marry in Arizona, Illinois, Indiana, Maine, Utah and Wisconsin if certain conditions apply, according to the NCSL. For instance, first cousins can marry in Indiana if both parties are 65 or older. In Maine, the couple must show proof of genetic counseling. Wisconsin cousins can marry if the woman is over the age of 55 and at least one person is unable to reproduce