World war I officially started on June 28th, 1914, when the Archduke and heir of the Australia Hungary throne, Franz Ferdinand, and his wife Sofia were assassinated. World War I was known as the European war but soon, countries beyond Europe's border became involved in the upheaval. America was not supposed to be involved - in fact, in the beginning, the war wasn't a threat to America. Woodrow Wilson was the President at the time that World War I started, and he decided that it would be best if America stayed neutral.
President Woodrow Wilson knew that the causes of the war weren't black and white and that the European conflict was an intricate and complicated issue. America stayed neutral for these reasons and America would be safe from any harm. As America watched the war from the sidelines for about two years, President Wilson was trying to create peace between Britain and Germany. President Wilson was very upset to hear that the Germans decided to unleash the use of U-boats. Germany announced that any merchant shipping in specified zones around Britain would be a target, and neutral ships were not excluded. The Germans felt that many allied ships started flying the neutral flag so that it could assist in their safety. .
President Wilson warned the Germans that if any German ships sank an American ship he would hold them accountable. In May 1915, the Lusitania was sunk by a German U-boat and 128 American civilians on board were killed. The Lusitania was not an American ship but the deaths of American's angered President Wilson. Germany pledged that it would not sink unarmed vessels, but it claimed that the Lusitania was carrying weapons. Later, the Germans would sink another ship, this one an Italian liner ultimately costing 27 American lives. After all of these attacks that took innocent American lives President Wilson and the America began the process of engaging in the war. .
The Zimmerman Telegram was a message that the Germans had sent to Mexico asking them to declare war on America.