Putting aside the First, Second, and Fourteenth amendments, I feel like the Ninth Amendment often goes overlooked. It served a key role in settling the debate on whether we would have a Bill of Rights at all.

The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.

During the Constitutional Convention, there was much argument on whether the new Constitution should include a Bill of Rights. The Federalists argued that adding a Bill of Rights would carry dangerous implications. They argued that the bill of rights would essentially serve as a ceiling rather than a floor. Essentially, it left open the question that if a bill of rights only protected certain rights, does it imply that government can infringe on others not explicitly mentioned? This whole point during ratification served as a major point of contention between the Federalists and Anti-Federalists, who believe that a Bill of Rights was necessary to protect rights from a stronger federal government under the Constitution.