The Constitution of the United States of America

The Federal Convention convened in the State House (Independence Hall) in Philadelphia on May 14, 1787, to revise the Articles of Confederation. Because the delegations from only two states were at first present, the members adjourned from day to day until a quorum of seven states was obtained on May 25. 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.
(Source: NARA web site)

About America: The Constitution of the United States of America With Explanatory Notes
A publication by the U.S. Department of State, Bureau of International Information Programs (IIP)

Constitution of the United States of America
This is a web site of the National Archives and Records Administration (NARA). Here you can find not only the text of the Constitution, but also some historical background, biographies of the Founding Fathers, and dozens of fascinating facts about the Constitution.

Bill of Rights
During the debates on the adoption of the Constitution, its opponents repeatedly charged that the Constitution as drafted would open the way to tyranny by the central government. Fresh in their minds was the memory of the British violation of civil rights before and during the Revolution. They demanded a "bill of rights" that would spell out the immunities of individual citizens. Several state conventions in their formal ratification of the Constitution asked for such amendments; others ratified the Constitution with the understanding that the amendments would be offered. On September 25, 1789, the First Congress of the United States therefore proposed to the state legislatures 12 amendments to the Constitution that met arguments most frequently advanced against it. The first two proposed amendments, which concerned the number of constituents for each Representative and the compensation of Congressmen, were not ratified. Articles 3 to 12, however, ratified by three-fourths of the state legislatures, constitute the first 10 amendments of the Constitution, known as the Bill of Rights.
(Source: NARA web site)

Plain text of the Constitution and the Amendments