Final answer:
The U.S Constitution was written and signed at Independence Hall in Philadelphia, Pennsylvania, on September 17, 1787, during the Constitutional Convention.
Step-by-step explanation:
The U.S Constitution was crafted during a secret meeting now known as the Constitutional Convention, held in the sweltering summer heat at Independence Hall in Philadelphia, Pennsylvania. After significant deliberation and numerous compromises, the final draft was ready. On September 17, 1787, the Constitution was signed by 39 of the 42 delegates present at the convention, marking a pivotal moment in American history and laying the foundation for the nation's legal and political framework. This moment was so crucial and symbolic that it has been commemorated in paintings, such as Howard Chandler Christy's 'Scene at the Signing of the Constitution of the United States,' which vividly captures the significance of the signing event. Though some states like Rhode Island took longer to ratify this profound document, its acceptance by all 13 states led to its eventual adoption as the law of the land. A reminder that even the mightiest documents start with pen and parchment.