Ninth Amendment (1791)
The Bill of Rights does not list every right that the people have. During the ratification debate, many called for a bill of rights to be added to the document. Federalists, who supported the Constitution as written, worried that a listing of certain rights would lead people to think that other rights were less important. The Ninth Amendment was added to try to prevent this misconception.
The Ninth Amendment implicitly refers to natural rights, which the Founders believed all people were born with as the gift of God or nature. As stated in the Declaration of Independence, they include life, liberty, and the pursuit of happiness. Many of the rights listed in the Bill of Rights, including several First Amendment freedoms, were also considered by the Founders to be among the natural rights of man, as well as practical means of ensuring justice in government. They believed that freedom from unreasonable government intrusion, as expressed in the Third, Fourth, and Fifth Amendments, was also a natural right.
Though the Supreme Court has never decided a case on the basis of the Ninth Amendment alone, the concurring opinion in Griswold v. Connecticut (1965) cited the Ninth Amendment as protecting a right of privacy within marriage.