## Facts

- John A. Barry and Eliza Ann (Mercein) Barry married in 1835 and later lived in New York.
- The marriage deteriorated; evidence portrayed Barry as hostile and overbearing toward his wife.
- The couple had two children: a son (Mercein Barry) and a daughter (Mary Barry).
- In 1838, Barry, his wife, and her father (Thomas Mercein) executed a separation agreement: the son would live with Barry in Nova Scotia, and the daughter would live with the mother at Mercein’s home in New York.
- After the separation, Barry returned to Nova Scotia with the son; the mother and daughter remained in Mercein’s household.
- Barry later sought Mary’s custody through habeas corpus, asserting a paramount paternal right and arguing he could not validly contract away custody.
- The mother and grandfather opposed transfer, citing Mary’s tender age, delicate health, need for maternal care, and the stability and support available in Mercein’s home.
- A single justice discharged the writ and refused to order Mary delivered to Barry; Barry sought review by certiorari in the New York Supreme Court.

## Issues

1. Whether habeas corpus is a proper vehicle to change custody of an infant between separated parents and a third-party household.
2. Whether a father’s common-law right to custody requires the court to award the child to him despite contrary welfare considerations.
3. What effect, if any, a voluntary separation agreement leaving a child with the mother should have on a habeas-based custody request.

## Decision

- The New York Supreme Court affirmed the order discharging the writ and declined to transfer custody to the father.
- The court recognized the father’s general common-law preference for custody but held it was not absolute in infant habeas proceedings.
- The court treated the child’s welfare—given her tender years, health, and settled placement with the mother—as the controlling consideration.
- The court concluded the child was not unlawfully restrained in the maternal grandfather’s home and that habeas relief was not warranted to disrupt the existing arrangement.

## Legal Principles

- In habeas corpus proceedings involving infants, courts may consider custody and welfare, not merely formal legal entitlement to possession.
- A father’s prima facie common-law right to custody of a legitimate minor child can be limited when the child’s welfare would be harmed by transfer.
- Where parents are voluntarily separated and the father has left a very young, sickly child with the mother, a court may refuse to change custody by habeas corpus, especially when the mother can provide stable care and support.
- A private separation agreement does not conclusively determine custody rights, but it may inform the court’s assessment of the parties’ voluntary arrangement and the child’s settled living situation.
- Habeas corpus will not be used to compel a custody transfer absent circumstances showing unlawful restraint or a custodial situation inconsistent with the child’s welfare.

## Conclusion

The court upheld denial of habeas relief, holding that a father’s custodial preference does not compel transfer of a tender, medically fragile child from the mother’s established home, and that the child’s welfare governs the custody determination in infant habeas proceedings.


People ex rel. Barry v. Mercein, 3 Hill 399 (N.Y. Sup. Ct. 1842)