· The U.S., as a neutral nation, claimed the right to trade with either side in the war.
· However, Britain and Germany set up blockades around the British and German coasts.
· German submarines, called U-boats, torpedoed enemy ships and neutral ships trading with the enemy.
· In 1915, a German submarine torpedoed the Lusitania, a British passenger ship, killing approximately 1,200 people, including 128 Americans.
· Americans were infuriated with the destruction of the Lusitania.
Zimmermann telegram:
– secret message from Germany to Mexico urging Mexico to attack the U.S. if the U.S. declared war on Germany
– Germany promised to help Mexico regain land it lost to the U.S. in the Mexican War.
* The U.S. declared war on the Central Powers in 1917.
