The United States of America did not always have a constitution. When the Revolutionary War ended, leaders from the different states got together and wrote a set of rules to figure out how to get along. These rules were called the Articles of Confederation. These rules gave a lot more power to the states than they did to the national government, which did not have a central ruler. After winning their freedom from England's monarchy, they worried that a central government could become too powerful. Do you think they were right to be worried about this? But their original plan did not work very well. States could not agree on important issues like taxes or national defense, and other nations did not consider the states "united" at all. So they tried again, and leaders from all 13 states came together in Philadelphia in 1787 for a Constitutional Convention to write a new set of rules.

This is a painting of the Constitutional Convention. Some leaders who were part of this convention include Benjamin Franklin, James Madison, and George Washington, among others. But not all the "founding fathers" were there. Patrick Henry refused to attend, and Thomas Jefferson and John Adams were too busy. There were a lot of arguments at the convention and several of the delegates threatened to walk out at various times. But the delegates continued to try to work out compromises. On September 17, the Constitution was signed by 39 of the original 55 delegates. Over the next two years, as the states ratified it, the Constitution became the basis for all American law.