On this day (April 6th) in 1917. The United States officially declares War on Imperial Germany. Entering the United States in to the Great War on the Allies side.
World War One officially starts on July 28, 1914 after the fallout of the assassination of Archduke Franz Ferdinand of Austria-Hungry on June 28th, 1914. The assassination lead to a serious of diplomatic and military maneuvers that at the start pitted Germany and Austro-Hungry against Russia, France, Serbia and the United Kingdom. Soon the Ottoman Empire and Bulgaria would also join the Centre Powers while Romania and Italy would join with the Allies
However what was thought to be a war that would be over by Christmas of 1914 soon turned out to be much more difficult and different then what was thought. Due to the advancement of industrial and military technologies that soon transformed from mobile mass maneuvering warfare into static trench warfare. Trench warfare lead to a statement of the Western Front while various wins and losses in the Eastern Front eventually lead to the collapse of Czarist Russia into its own brutal Civil War effectively ending the Eastern Front after Russia’s surrender.
At the time The United States was officially neutral however there were strong debates within the United States after the German sinking of Lusitania, Unrestricted submarine warfare, Invasion of Belgium Neutrality, Allie and Centre Power Propaganda and crimes. With various groups within America strongly favoring entering the war (mainly on the allies by the time of the United States official declaration of war) or staying completely neutral from the Great War, or “The war to end all wars” as H. G. Wells coined during the early part of the war.
By the end of the Great War the United States had mobilized 4.734 million soldiers with 116 thousand deaths and 204 thousand wounded. (According to American War and Military Operations Casualties: Lists and Statistics January 2015) The war leaving behind a legency that we are still graphing with even today.