It is a logical question, with a surprising answer. Historically, unmarried fathers have had fewer Constitutional rights with regard to their children than either unwed mothers or married parents. Over the past several decades, unmarried fathers have challenged the termination of their parental rights under the Fourteenth Amendment in cases in which birth mothers relinquished their children for adoption. In a series of cases involving unmarried fathers, the U.S. Supreme Court affirmed the constitutional protection of such a father’s parental rights when he has established a substantial relationship with his child. The court found that the existence of a biological link between a child and a putative father gives the father the opportunity to establish a substantial relationship, which it defined as the father’s commitment to the responsibilities of parenthood, as demonstrated by being involved or attempting to be involved in the child’s upbringing. Nevertheless, States have almost complete discretion to determine the rights of unmarried fathers whose legal relationship to a child has not been established for the purposes of termination of parental rights or adoption proceedings.