Traditionally, under the common law, a father of a child born out of wedlock had no rights. The mother of an illegitimate child had the primary right to custody. In some jurisdictions, she even had the exclusive right to custody of any children. In fact, the mother could even remarry and the new husband could adopt the out of wedlock child without getting consent from the biological father or even giving him notice of the impending adoption of his child.

Some states took steps to protect unmarried fathers’ rights. Under New York law, unmarried fathers have a right to a hearing if the child is going to be adopted. A solution contained in UPA (2000) is a registry that provides a clearinghouse of potential fathers’ contact information so they can be joined in any adoption proceeding. As with all decisions involving children, courts apply the "best interests of the child" test.

The general rule that preferred mothers in custody disputes has been challenged as unconstitutional. Subsequently, any statutes that automatically deny the fathers’ rights have been judged to be unconstitutional.

Example: Joan Stanley lived with Peter Stanley intermittently for 18 years, during which time they had three children. When Joan Stanley died, the State declared that Peter’s three out of wedlock children were wards of the state pursuant to Illinois law that the children of unwed fathers became wards of the State upon the death of the mother. The Supreme Court held that denying parents the right to a hearing as to their fitness as parents based on a statutory classification violated equal protection rights.

“We conclude that as a matter of due process of law, Stanley was entitled to a hearing on his fitness as a parent before his children were taken from him and that by denying him a hearing and extending it to all other parents whose custody of their children is challenged the State denied Stanley the equal protection of the law guaranteed by the Fourteenth Amendment.” See, e.g., Stanley v. Illinois, 405 U.S. 645, 92 S. Ct. 1208, 31 L.Ed.2d 551 (1972).

The statute was declared overbroad and any automatic denial of the father’s rights is unconstitutional as it is unequal to the rights of a father who had married the mother. Had the couple been married, the father/husband would have automatically gotten custody of the children. Similarly, a divorced father was also entitled to automatic custody. Unmarried fathers who had nothing to do with their children would be in the same position as the plaintiff in Stanley.

Even before Stanley, Peter Stanley (the plaintiff) had other options when his children became wards of the state. He could have met with the officials or the child welfare agency and proved he was the father. He could have adopted the children, brought a paternity action or become the children’s guardian ad litem. Despite his choices, Stanley went to court and had the statute declared unconstitutional, preventing further mishaps for other fathers.

The automatic rule that the father is excluded from seeking custody of his child has been abolished. Instead, after Stanley the father would be entitled to notice and a hearing to determine whether he is fit before he is denied custody. In addition, most courts abandon such preferences for the mother. This equal access also applies to the right to visitation.

Another result of the equal protection challenge to the historical preference for the mother is an equivalent obligation to support their illegitimate children just as they must support their legitimate children. As such, fathers cannot avoid their support obligations just because they chose not to marry the child’s mother.

Historically, an illegitimate child was prevented from inheriting from both the father and mother. Today, most states have abolished this rule and permit equal inheritance rights. The unconstitutionality of the prohibition against inheriting from the father was decided in Trimble v. Gordon, 430 U.S. 762, 97 S. Ct. 1459, 52 L.Ed.2d 31 (1977). Some states, however, require paternity to be established during the father’s lifetime via a decree of filiation in a paternity suit before the child can inherit from the father. See, e.g., N.Y. Est. Powers & Trusts Law § 4-1.2 (1981).