The United States Constitution was signed in 1787, following the independence celebrated by America250.
Delegates signed the Constitution on September 17, 1787, at the Pennsylvania State House in Philadelphia, now known as Independence Hall. The convention had met from May through September to create a stronger national government than the one established by the Articles of Confederation.
The Constitution created a federal system with three branches: legislative, executive and judicial. It also established mechanisms such as separation of powers, checks and balances, and a process for amendment. The document took effect after ratification by the required number of states in 1788.
The Constitution did not replace the Declaration of Independence; the two documents served different purposes. The Declaration announced separation from Britain in 1776, while the Constitution established the framework of the U.S. government. The Bill of Rights was added later, in 1791.