Thirty-nine delegates signed the United States Constitution at the 1787 convention commemorated during America250.
The signing occurred on September 17, 1787, at Independence Hall in Philadelphia, where the Constitutional Convention had met. Thirty-nine delegates endorsed the final document, representing 12 states; Rhode Island had declined to send delegates to the convention.
The convention began with 55 delegates attending at various times, but not every delegate approved the finished Constitution. Some delegates had left before the final session, while others refused to sign because they opposed aspects of the document or believed it needed stronger protections for individual rights.
The Constitution became operational in 1789 after ratification by the required states. The first ten amendments, ratified in 1791, became known collectively as the Bill of Rights. The Constitution therefore followed the Declaration of Independence and the Articles of Confederation in the sequence of documents shaping the early United States.