World War I was a watershed moment for America, a time when an isolationist nation involved itself in world affairs and began the rise to the economic and military power that America is today. After keeping out of the conflict that had been ravaging Europe for nearly three years, President Woodrow Wilson took America to war only months after winning an election on the slogan "He Kept us Out of War." Claiming that American intervention was needed to "make the world safe for democracy," Wilson sent over two million men to Europe, of whom over 100,000 would never return. World War I marked the end of the old order in Europe, and the beginning of what has been called the "American Century."