The United States Constitution and the Declaration of Independence are the two greatest documents ever penned in human history. The U.S. Constitution was written principally by James Madison, and it is the oldest written constitution still used by any nation. It serves as the framework for the organization of the United States government and for the relationship of the federal government with the states, citizens, and all people within the United States. The Declaration of Independence was adopted by the Continental Congress on July 4, 1776. It announced that the thirteen American colonies, then at war with Great Britain, were now independent states and thus no longer a part of the British Empire. Written primarily by Thomas Jefferson, the Declaration is a formal explanation of why Congress had voted on July 2 to declare independence from Great Britain, more than a year after the outbreak of the American Revolutionary War. The birthday of the United States of America���Independence Day���is celebrated on July 4, the day the wording of the Declaration was approved by Congress.