The American Revolution articulated ideals of universal liberty, but for more than a century the United States had little political or diplomatic involvement with other nations. A republic in a world dominated by imperial monarchies, the United States avoided the dynastic quarrels, territorial disputes and diplomatic maneuvers that consumed the European state system through most of the nineteenth century. The United States provided the world with proof that a system of government based on the popular will and dedicated to the interests of ordinary people can be effective, but made no effort to export the ideals of the American Revolution or to promote the spread of republican institutions.

The United States entered World War I to defend freedom and democracy against tyranny and oppression, inspired by the ideals of the American Revolution and the memory of the Revolutionary War. The war transformed the nation’s political and cultural relationship with Europe and shaped a new determination to spread the principles of the American Revolution around the world. The war also changed the way Americans imagined and remembered the American Revolution.

“The American Revolution,” President Woodrow Wilson explained, “was a beginning, not a consummation, and the duty laid upon us by the beginning is the duty of bringing the things then begun to a noble triumph of completion.”  A century after the United States embarked on that great crusade, the legacy of the American Revolution continues to shape our relationships around the world. “America has a great cause,” President Wilson reminded us, “which is not confined to the American continent. It is the cause of humanity itself.”

The Great Crusade opened the week of April 6, 2017—the one hundredth anniversary of the American declaration of war on Germany.