US Neutrality.

During the industrial era, the United States was in much need for raw materials in order to feed its economy. Local resources were not enough, therefore the United States needed to get these materials from other countries. As a result, the United States opted for imperialism; The United States achieved a lot during this era. The United States was not alone in these race for territories. In order to achive the conquering of many foreign territories a vast expansion of the army was needed. The use of these armies was to intimidate other nations, this is also known as militarism. Moreover, imperialims created distrust among the imperialist which ultimately resulted in the creation of secret military alliances.
All this factors, along with the rise of nationalism by those conquered by imperialist, were the creators of Wolrd War one which lasted from 1914 to 1918. As the war broke out with the assassination of heir to the Austro-Hungarian throne, Francis Ferdinand, the United States declared their neutrality. The United States was in fact neutral, until a number of factors forced the nation to intervene along with the allies.
By 1914, the United States president at the time, Woodrow Wilson, declared the nations neutrality, ( Doc A ) stating that the war was not in the best of interest for the nation. National leaders such as Secretary of State William Jennings Bryan also gave voice to the inclination for American neutrality (Doc D).The United States remainded neutral, until Germany along with its unrestricted submarine warfare in european seas resulted in the lost lives of hundreds of Americans. This action of course upset the United States. As stated by the German embassy, (doc E) any ship sailing in the warzone would be attacked. Since the United States still traded with european nations, this was a big problem for the nation. In response, the United States president declared to cut off all kinds of dipolomatic relationships with Germany unless the unrestricted Warfare stoped.( Doc G) Germany wanted to keep the United States out of conflict therefore they promised not to sink any ships without warning or taking care for the lives of passengers, this was known as the Sussex Pledge.
Deeper United States involvement in war came in 1917 when Germany decided to continue with their Submarine Warfare. The U.S. declared "Armed neutrality" , this meant that U.S. merchant ships would be armed to protect themselves from German U-Boats. Germany realized that this was a small step into bringing the U.S. into war; They also thought that it was too late however for American intervention to have any effect in the outcome of war. Just in case the U.S. became too involved in war, Germany's Arthur Zimmerman sent a telegram to German Ambassador Johann von Bernstoff in Mexico. (Doc H) The telegram was intercepted by the British however. The telegram encouraged Mexico to join Germany's cause in case the U.S. joined war. If Germany won, Mexico would get back the lasn lost to the U.S. during the Mexican-American War. This angered the Americans.
Later on, the United States entered War in order "to make the World safe for democracy." Now the United States was beginig to see Germany as a threat to the world ( Doc I). Fortunately U.S. intervention was very helpful since its help was a big factor to defeating the Germans. After war ended, Wilson and the Allies came up with the Treaty of Versailles and the League of Nations.
By the begining of the war the U.S. still traded with Britain and even Germany, however, since Germany decided to use Submarine Warfare and take the lifes of people, including Americans, the United States could not keep its neutrality for too long. Due to the fact that Germany was a threat to American lifes as well as the rest of the world, U.S involvement was necessary in order to stop Germany's awful militaristic plans.