The constitution before the Constitution
On July 4, 1776, representatives of the 13 American colonies met at the Continental Congress and approved the Declaration of Independence. In the Declaration, the 13 former colonies referred to themselves as the United “States,” because each state considered itself, not only independent of Great Britain, but also independent (at least to an extent) of the other newly formed states.

One year later, representatives of the states meeting at the Continental Congress drafted the Articles of Confederation, the first constitution of the new country. The Articles of Confederation provided for a loose union among the States as they fought the Revolutionary War against Great Britain.
Weakness of the Articles of Confederation
But the Articles of Confederation established a weak national government. The Articles created a legislative body, Congress, however, there was no executive branch nor a judicial branch. Congress did not have the power to tax nor did it have the power to regulate commerce.
What were some things the Congress could do? Congress could establish embassies and settle disputes between states. Congress could print money, but so could the states.
Replacing the Articles of Confederation
Recognizing that the government created by the Articles of Confederation was too weak, Congress met to revise the Articles after the Revolutionary War. After much debate and compromise, the states replaced the Articles of Confederation with the Constitution of the United States. But it was not an easy process.