After the Articles of Confederation were ratified, the document created to govern the United States was the United States Constitution. The Constitution was drafted in 1787 by a group of delegates, including James Madison, George Washington, and Benjamin Franklin, who convened at the Constitutional Convention in Philadelphia. The Constitution established a federal system of government with a separation of powers between the three branches of government: the legislative, executive, and judicial branches. It also included a system of checks and balances to prevent any one branch from becoming too powerful. The Constitution was eventually ratified by the required number of states in 1788 and went into effect the following year, replacing the weaker government established by the Articles of Confederation. The Constitution remains the supreme law of the United States to this day and is considered one of the most important documents in American history.