No, it is illegal to marry your first cousin in New Hampshire. The state’s law explicitly prohibits such unions, making New Hampshire unique among New England states for this restriction.
New Hampshire’s Marriage Law
New Hampshire Revised Statutes Section 457:2 lists prohibited relationships, including “father’s brother’s son” or “father’s brother’s daughter,” which defines first cousins by blood. This statute, dating back to the 1800s with updates as recent as 2009, voids first-cousin marriages performed in-state or out-of-state if residents return.
Local officials, like the Town of Exeter clerk, confirm: “Marriage is not permitted… between people who are related by blood as first cousins or in any more direct lineage.”
What Counts as a First Cousin?
First cousins share grandparents but not parents, such as the child of your parent’s sibling. The law targets blood relations only; adoptive cousins cannot marry either, but step-cousins or in-laws face no such bar. First cousins once removed (e.g., your parent’s first cousin) or second cousins are allowed to wed.
Penalties and Enforcement
No criminal penalty exists for attempting a first-cousin marriage in New Hampshire—it’s not a crime, just void ab initio (invalid from the start). Couples can cohabitate or have sexual relations legally, unlike in stricter states. Out-of-state cousin marriages by New Hampshire residents are also voided upon return, preventing workarounds.
Comparison to Other States
New Hampshire bans first-cousin marriage outright, unlike neighbors:
This places New Hampshire among 25 states prohibiting it as of 2025.​
Historical Background
Cousin marriage bans swept U.S. states post-Civil War, fueled by eugenics fears of genetic defects in offspring, despite mixed science. New Hampshire’s law evolved from 19th-century statutes amid concerns over “idiocy” and inbreeding, though modern data shows first-cousin children have only a 4-7% higher risk of birth defects versus 3-4% general. The National Conference of Commissioners recommended repealing such bans in 1970, but New Hampshire retains it.
Genetic and Health Considerations
First cousins share about 12.5% DNA, raising recessive disorder risks slightly, but experts note environment and screening matter more. No mandate for counseling exists in New Hampshire, unlike Maine. Public health views bans as outdated, with low U.S. incidence (under 0.2% of marriages).
Cultural and Global Context
In India, cousin marriages are common (10-20% in some regions) and legal, contrasting U.S. norms rooted in Christianity and eugenics. Globally, over 1 billion people descend from cousin unions, legal in most countries except parts of the U.S. and China. For Indian-Americans in New Hampshire, this law applies regardless of origin.
Practical Advice for Couples
Check lineage via family trees before applying for a license—clerks verify applications. Marry elsewhere where legal (e.g., Massachusetts), but know New Hampshire won’t recognize it if you reside there. Consult a family lawyer for inheritance or custody implications, as void marriages affect rights. No recent changes as of March 2026
SOURCES:
- https://en.wikipedia.org/wiki/Cousin_marriage_law_in_the_United_States
- https://wokq.com/is-it-legal-to-marry-your-first-cousin-new-hampshire/
