From the summer of 1787

"We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America."
From www.archives.gov

The Federal Convention convened in the State House (Independence Hall) in Philadelphia on May 14, 1787, to revise the Articles of Confederation...Through discussion and debate it became clear by mid-June that, rather than amend the existing Articles, the Convention would draft an entirely new frame of government. All through the summer, in closed sessions, the delegates debated, and redrafted the articles of the new Constitution. Among the chief points at issue were how much power to allow the central government, how many representatives in Congress to allow each state, and how these representatives should be elected--directly by the people or by the state legislators. The work of many minds, the Constitution stands as a model of cooperative statesmanship and the art of compromise.

Click here for the rest of the transcript of the Constitution.