Longest Continuously Operative Single-Document National Constitution

Delegates signed the final constitutional text in Philadelphia on 17 September 1787. The document was submitted to state ratification conventions, with New Hampshire becoming the ninth state to ratify it on 21 June 1788, meeting the prescribed threshold.

The National Archives distinguishes adoption and ratification from government operation. The new federal government legally began on 4 March 1789, although Congress reached a quorum only in April and the executive and judiciary were organized over subsequent months. The record therefore uses 4 March 1789 as its operational start.

This is not a claim that the United States has the world's earliest written constitutional provisions: San Marino's earlier statutes form part of a different, multi-document constitutional system. The United States Constitution has undergone 27 amendments without replacement by a new founding charter.