The United States remained neutral from the outbreak of World War I in 1914 until 1917 when it joined the war as an "associated power" alongside the Allies of World War I, helping to turn the tide against the Central Powers. In 1919, President Woodrow Wilson took a leading diplomatic role at the Paris Peace Conference and advocated strongly for the U.S. to join the League of Nations. However, the Senate refused to approve this and did not ratify the Treaty of Versailles that established the League of Nations.[117]
In 1920, the women's rights movement won passage of a constitutional amendment granting women's suffrage.[118] The 1920s and 1930s saw the rise of radio for mass communication and the invention of early television. The prosperity of the Roaring Twenties ended with the Wall Street Crash of 1929 and the onset of the Great Depression. After his election as president in 1932, Franklin D. Roosevelt responded with the New Deal.[120] The Great Migration of millions of African Americans out of the American South began before World War I and extended through the 1960s;[121] whereas the Dust Bowl of the mid-1930s impoverished many farming communities and spurred a new wave of western migration.[122]