The U.S. Constitution came into effect on March 4, 1789. After being drafted at the Constitutional Convention in 1787, the document was ratified by the necessary nine states by June 1788. However, it was not until 1789 that the new government under the Constitution officially began its operations. This marked the establishment of the framework for the federal government, outlining the powers of its branches, the rights of the states, and the rights of citizens. The Constitution remains the supreme law of the United States and serves as a cornerstone of American democracy.