1. Steps Toward War On May 7, 1915, a German U-boat/submarine torpedoed the British passenger ship Lusitania as it crossed the Atlantic Ocean. – Ship was carrying weapons for the Allies. – 128 Americans were killed. Americans protested to Wilson. In response, Germany announced its submarines would stop attacking nonmilitary ships. – Made announcement to Americans to stay off British vessels, or those of its allies.

3. Germany Breaks its Promise On February 1, 1917, Germany began unrestricted submarine warfare – Believed they could conquer Great Britain before the U.S. entered the war. – Several American merchant ships were torpedoed.

4. Zimmerman Telegram March 1, 1917, a German foreign minister asked the German ambassador to Mexico to extend an offer: – Mexico would declare war against the U.S. if the U.S. entered the war in Europe. – In return, Mexico would receive New Mexico, Texas and Arizona.

8. Final Straw Later in March of 1917 German U-boats (submarines) sank four U.S. ships. On April 2, 1917, Wilson asked Congress for a declaration of war against Germany.