James Monroe was the sixth President of the United States and succeeded James Madison in 1817. He was a Founding Father, having signed the Declaration of Independence, and served as the fifth Governor of Virginia. Monroe is best remembered for his foreign policy, which became known as the Monroe Doctrine. This doctrine declared that the United States would not interfere in European affairs and that any attempt by a European power to colonize or interfere with states in North or South America would be seen as an act of aggression against the United States.