section_path: History/Rise as a superpower (1917 – 1945)
section_name: Rise as a superpower (1917 – 1945)
paragraph_text: Rise as a superpower (1917 – 1945)
  
  The United States entered World War I alongside the Allies of World War I, helping to turn the tide against the Central Powers. In 1920, a constitutional amendment granted nationwide women's suffrage. During the 1920s and '30s, radio for mass communication and the invention of early television transformed communications nationwide. The Wall Street Crash of 1929 triggered the Great Depression, which President Franklin D. Roosevelt responded to with the New Deal, a series of sweeping programs, public work projects, financial reforms, and regulations.
  
  Initially neutral during World War II, the U.S. began supplying war materiel to the Allies of World War II in March 1941 and entered the war in December after the Empire of Japan 's attack on Pearl Harbor. The U.S. developed the first nuclear weapons and used them against the Japanese cities of Hiroshima and Nagasaki in August 1945, ending the war. The United States was one of the " Four Policemen " who met to plan the post-war world, alongside the United Kingdom, Soviet Union, and China. The U.S. emerged relatively unscathed from the war, with even greater economic power and international political influence.