The event that angered Americans and compeled the US government to send two strongly worded warnings to Germany in 1915 was the sinking of the Lusitania.
The sinking of the RMS Lusitania, which occurred off the coast of Ireland on May 7, 1915 due to the attack of a German submarine, was one of the greatest naval disasters to have occurred to a line ship during the First World War.
The Lusitania was identified and torpedoed by a submarine U-boat U-20 and sank in 18 minutes, near the Cape of Old Head of Kinsale, killing 1,198 people and leaving 761 survivors. The sinking made public opinion in many countries opposed mainly to Germany, contributing to the United States' entry into the war, and became a symbol of military recruitment campaigns.
Of the 139 American passengers aboard the Lusitania, 128 lost their lives, which produced massive anger in both Britain and the United States. The Nation newspaper called it "a debt for which a Hun would blush with embarrassment, a Turk would feel ashamed, and a barbarian pirate would apologize", while the British felt that the United States should immediately declare war on Germany. Nonetheless, US President Woodrow Wilson refused to overreact.
