MR. JUSTICE WHITE delivered the opinion of the Court.

Joan Stanley lived with Peter Stanley intermittently for 18 years, during which time they had three children. When Joan Stanley died, Peter Stanley lost not only her but also his children. Under Illinois law, the children of unwed fathers become wards of the State upon the death of the mother. Accordingly, upon Joan Stanley’s death, in a dependency proceeding instituted by the State of Illinois, Stanley’s children were declared wards of the State and placed with court-appointed guardians. Stanley appealed, claiming that he had never been shown to be an unfit parent and that since married fathers and unwed mothers could not be deprived of their children without such a showing, he had been deprived of the equal protection of the laws guaranteed him by the Fourteenth Amendment. The Illinois Supreme Court accepted the fact that Stanley’s own unfitness had not been established but rejected the equal protection claim, holding that Stanley could properly be separated from his children upon proof of the single fact that he and the dead mother had not been married. Stanley’s actual fitness as a father was irrelevant.

Stanley presses his equal protection claim here. The State continues to respond that unwed fathers are presumed unfit to raise their children and that it is unnecessary to hold individualized hearings to determine whether particular fathers are in fact unfit parents before they are separated from their children. We granted certiorari to determine whether this method of procedure by presumption could be allowed to stand in light of the fact that Illinois allows married fathers—whether divorced, widowed, or separated—and mothers—even if unwed—the benefit of the presumption that they are fit to raise their children. . . .

We must therefore examine the question that Illinois would have us avoid: Is a presumption that distinguishes and burdens all unwed fathers constitutionally repugnant? 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 laws guaranteed by the Fourteenth Amendment. . . .

The Court has frequently emphasized the importance of the family. The rights to conceive and to raise one’s children have been deemed “essential,” “basic civil rights of man,” and “rights far more precious. . .than property rights.” “It is cardinal with us that the custody, care and nurture of the child reside first in the parents, whose primary function and freedom include preparation for obligations the state can neither supply nor hinder.” The integrity of the family unit has found protection in the Due Process Clause of the Fourteenth Amendment, Meyer v. Nebraska, the Equal Protection Clause of the Fourteenth Amendment, Skinner v. Oklahoma, and the Ninth Amendment, Griswold v. Connecticut. . . .

It may be, as the State insists, that most unmarried fathers are unsuitable and neglectful parents. It may also be that Stanley is such a parent and that his children should be placed in other hands. But all unmarried fathers are not in this category; some are wholly suited to have custody of their children. This much the State readily concedes, and nothing in this record indicates that Stanley is or has been a neglectful father who has not cared for his children. Given the opportunity to make his case, Stanley may have been seen to be deserving of custody of his offspring. Had this been so, the State’s statutory policy would have been furthered by leaving custody in him. . . .

The State of Illinois assumes custody of the children of married parents, divorced parents, and unmarried mothers only after a hearing and proof of neglect. The children of unmarried fathers, however, are declared dependent children without a hearing on parental fitness and without proof of neglect. Stanley’s claim in the state courts and here is that failure to afford him a hearing on his parental qualifications while extending it to other parents denied him equal protection of the laws. We have concluded that all Illinois parents are constitutionally entitled to a hearing on their fitness before their children are removed from their custody. It follows that denying such a hearing to Stanley and those like him while granting it to other Illinois parents is inescapably contrary to the Equal Protection Clause.

The judgment of the Supreme Court of Illinois is reversed and the case is remanded to that court for proceedings not inconsistent with this opinion.

It is so ordered. . . .

MR. CHIEF JUSTICE BURGER, with whom MR. JUSTICE BLACKMUN concurs, dissenting. . . .

In regard to the only issue that I consider properly before the Court, I agree with the State’s argument that the Equal Protection Clause is not violated when Illinois gives full recognition only to those father-child relationships that arise in the context of family units bound together by legal obligations arising from marriage or from adoption proceedings. Quite apart from the religious or quasi-religious connotations that marriage has—and has historically enjoyed—for a large proportion of this Nation’s citizens, it is in law an essentially contractual relationship, the parties to which have legally enforceable rights and duties, with respect both to each other and to any children born to them. Stanley and the mother of these children never entered such a relationship. The record is silent as to whether they ever privately exchanged such promises as would have bound them in marriage under the common law. In any event, Illinois has not recognized common-law marriages since 1905. Stanley did not seek the burdens when he could have freely assumed them. . . .

The Illinois Supreme Court correctly held that the State may constitutionally distinguish between unwed fathers and unwed mothers. Here, Illinois’ different treatment of the two is part of that State’s statutory scheme for protecting the welfare of illegitimate children. In almost all cases, the unwed mother is readily identifiable, generally from hospital records, and alternatively by physicians or others attending the child’s birth. Unwed fathers, as a class, are not traditionally quite so easy to identify and locate. Many of them either deny all responsibility or exhibit no interest in the child or its welfare; and, of course, many unwed fathers are simply not aware of their parenthood.

Furthermore, I believe that a State is fully justified in concluding, on the basis of common human experience, that the biological role of the mother in carrying and nursing an infant creates stronger bonds between her and the child than the bonds resulting from the male’s often casual encounter. This view is reinforced by the observable fact that most unwed mothers exhibit a concern for their offspring either permanently or at least until they are safely placed for adoption, while unwed fathers rarely burden either the mother or the child with their attentions or loyalties. Centuries of human experience buttress this view of the realities of human conditions and suggest that unwed mothers of illegitimate children are generally more dependable protectors of their children than are unwed fathers. While these, like most generalizations, are not without exceptions, they nevertheless provide a sufficient basis to sustain a statutory classification whose objective is not to penalize unwed parents but to further the welfare of illegitimate children in fulfillment of the State’s obligations as parens patriae.