Today in 1915, a German U-boat submarine fires at, and sinks, the Lusitania killing many of its passengers. During the midst of World War I, Germany had U-boats patrolling the seas in hunt of enemy ships to take out. Understanding this, Britain gave warning to the Lusitania to avoid the coast of Ireland. The Lusitania ignored the simple warning and proceeded through the waters with little caution. This gave the German submarines to sink the Lusitania, which they viewed as an enemy ship with supplies.
However, the Lusitania was mainly a passenger ship that saw the loss of many women and children, as well as 128 Americans. Upon learning about the attack, U.S. president Woodrow Wilson sent a strong letter to the Germans asking them to stop firing on innocent ships. Germany, although not wanting to, agreed to end the unrestricted attacks, and declared the area around Britain a war zone. Germany would not hold up the deal forever, and in 1917 resumed the unrestricted attacks. President Wilson wasted no time letting the Germans know they were being cut off due to their actions. The Germans would later sink the U.S. ship Housatonic. Although neutral for most of the war, the U.S. officially entered in April of 1917.