The Ninth Amendment to the United States Constitution addresses rights, retained by the people, that are not specifically enumerated in the Constitution. It is part of the Bill of Rights. The amendment was introduced during the drafting of the Bill of Rights when some of the American founders became concerned that future generations might argue that, because a certain right was not listed in the Bill of Rights, it did not exist. However, the Ninth Amendment has rarely played any role in U.S. constitutional law, and until the 1980s was often considered "forgotten" or "irrelevant" by many legal academics.

The Federalist Papers is a collection of 85 articles and essays written by Alexander Hamilton, James Madison, and John Jay under the collective pseudonym "Publius" to promote the ratification of the Constitution of the United States. The collection was commonly known as The Federalist until the name The Federalist Papers emerged in the twentieth century.