In the United States, many children are born to unwed parents every day. In fact, the Center for Disease and Control and Prevention states that 41 percent of all babies born in America do not have legally married parents. In general, unmarried mothers are usually given sole physical and legal custody of their child at the beginning of the baby's life. This is because there is normally no debate that the woman who was pregnant with the child is his or her biological parent. For men, it is more difficult to prove legal and physical fatherhood.

Because a mother has original jurisdiction over her child, she may desire to put the baby up for adoption. In many instances, fathers will challenge their Fourteenth Amendment rights if this situation arises. Due to a number of cases concerning this issue, the Supreme Court has ruled that the constitutional protection of a father's rights may be invoked if he has a substantial relationship with his child. A substantial relationship is determined by the father's involvement in his child's life, as well as his role in the upbringing of that child.

There are other reasons that a father may want to declare parentage. If legally recognized, parentage will allow him to receive notification of court proceedings regarding the child, all petitions for adoption, and any actions the mother may take to terminate his parental rights. Legally recognized fathers may be able to receive court-appointed visitation time with their child. A father can obtain notification if the child's mother plans to move out of state, or if the mother is planning to give someone else temporary custody of the child. They are also able to get holiday time or vacation time with their child by order of the court. If a father has been denied parenting time, claiming legal paternity can allow him to make that time up.

According to the Child Welfare Department, there is no standard definition for the word 'father' in the United States. Some states will recognize a "putative father" as a man who is alleged to be that child's biological father and has a legal relationship to a child that has not been established. Putative fathers are not married to the mother of the child, or were not married to that woman at the time of the child's birth.

In 22 states, putative fatherhood is based on a series of qualifications. First of all, if the man was married to the child's mother, and the child is born in the marriage, or within 300 days after the marriage ended, then he is declared the father. In the event that the a man and woman attempted to marry but the marriage was declared invalid, and the child is born during the marriage or 300 days after the marriage is terminated, then a man can claim fatherhood. If he consented to be listed the father on his child's birth certificate, has acknowledged his paternity in writing, or has committed to financially supporting the child, then many states will recognize this as proof for parentage. 22 states will recognize fatherhood if a child lived with the claimant as a minor and he claims biological fatherhood. Genetic testing can also help to clarify parentage issues when other methods fail.

24 states allow fathers to record parentage in a putative father registry. In 11 states, a father can file documents with the social security department to declare parentage of a child. 21 states allow a person to file an affidavit in court to claim parentage. Paternity can also be established by a court order in every state in the U.S. if officials deem in necessary and beneficial to the child. 44 states allow a father to rescind his claim for paternity. 15 states of that states that permit this action state that it can occur at any time. In Florida, a father may only retract his paternity claim prior to the child's birth, and in Arkansas and Iowa, a parent can only make this claim after the child is born. 20 states limit rescission to 60 days after a paternity claim is submitted and prior to a court proceeding. 19 states will not retract a paternity claim after this 60 day window unless it is by court intervention for a crime.

Registered unmarried fathers are given the same responsibility as a married father, including financial obligations for the child, and a role in the child's upbringing. Parents who are seeking declared paternity from a court may need to provide their name, address, social security number, and date of birth. These fathers may also need to obtain the date of birth of the child's mother. Some states require the name and address of any person that has claimed to be the child's father, and others will demand the child's name and date of birth, or expected month and year of the child's birth. Anyone who is specially interested and affiliated with a paternity case has the right to access state records regarding the child. Birth mothers, adoption agencies, possible adoptive parents, and state organizations can open up these documents for their case. To get more information about your rights as an unmarried father, contact a family law attorney.