• The Assassination of Archduke Franz Ferdinand

    In June of 1914, the heir to the Austro-Hungarian throne was shot and killed by assassins in order to gain land. This led to Germany attacking Belgium and France in August 1914.
  • The Sinking of the Lusitania

    German U-boats, or submarines, sunk ships going between England and America. On May 7, 1915, a German boat sank the Lusitania, a British passenger ship sailing off the coast of Ireland. More than 100 Americans were killed. The Germans said they had put warnings in American newspapers telling passengers to stay off ships heading to the war zone. Germany also said the Lusitania had been carrying war supplies for England.
  • The Zimmermann Telegram

    Arthur Zimmermann, a German leader, sent a telegram to Mexico asking the country to start a border war with the United States. In return, Germany would get back Mexican land that had become Texas, New Mexico and Arizona. The English got a copy of the telegram, broke the secret code and sent the information to Wilson.
    The telegram was put in the U.S. newspapers, showing that Germany was America's enemy. Two months later, German boats sank three American merchant ships.
  • The United States Enters the War

    After the Zimmermann Telegram, Wilson asked Congress for a declaration of war on April 2, 1917. Wilson said the United States must go to war because the world “must be made safe for democracy.” War was officially declared against Germany on April 6, 1917.
    World War I involved all Americans. The government set goals for manufacturing, farming, transportation and selecting men for the military. Patriotic posters, pamphlets, films and public speakers encouraged Americans to support the war.
  • Why did the United States try to remain neutral?

    Americans debated for two and a half years about joining the war. In 1914, President Woodrow Wilson said the United States would stay neutral, because many Americans were immigrants from countries of both the Central Powers and the Allies. They disagreed over which countries had started the war and which countries should be supported by America, so Wilson urged Americans not to take sides.