By 1787, the young nation had found the Articles of Confederation lacking. That summer, delegates convened in Philadelphia to revise them. Through discussion and debate, the delegates decided that, rather than amend the existing Articles of Confederation, the Convention would draft an entirely new constitution.
The Preamble to the United States Constitution announces the purposes of the new government:
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.
During the debates over a new constitution, John Adams' model of government was extremely influential. Like the Massachusetts Constitution, the United States Constitution establishes three branches of government:
- an executive branch headed by a President,
- a legislative branch known as the Congress, and consisting of a Senate and House of Representatives, and
- an independent judicial branch headed by a Supreme Court.
On September 17, 1787, the Constitutional Convention approved the Constitution of the United States and submitted it to the states for ratification.
John Adams, then serving as Ambassador to Great Britain, missed the Constitutional Convention, but actively participated from across the Atlantic Ocean. In 1787, he published his persuasive Defense of the Constitutions of Government of the United States of America, which restated his case for a balanced government. Adams also corresponded extensively with those who were writing the Constitution.
When Adams saw the proposed United States Constitution, he was disappointed by the absence of a Declaration (or Bill) of Rights. On November 10, 1787, he wrote to Thomas Jefferson, who was serving as Ambassador to France , "What think you of a Declaration of Rights? Should not such a thing have preceded the model?" Adams supported both ratification of the United States Constitution and the prompt addition of a Bill of Rights.
The United States Constitution was ratified in June 1788. The new Congress approved a Bill of Rights in 1789, which was ratified in 1791.
In 1789, George Washington was elected President of the United States, and John Adams was elected Vice President.