In the early years of the 20th century, the most famous Americans on the national stage were Theodore Roosevelt, Woodrow Wilson, and Jane Addams—two presidents and a social worker. Each took a different path to prominence, yet each believed the United States must assume a more dynamic role in confronting domestic and international problems. Following the outbreak of World War I in 1914, the views of these the three progressives grew sharply apart, and as Neil Lanctot discusses here, American politics fractured in their wake.