World War I, also known as "The Great War" was a four-year conflict that began in Eastern Europe and spread to include countries in the United Kingdom, the Pacific and the United States.
What Were the Causes of World War I?
Though there were many political frustrations, issues of nationality and land struggles that combined to set the stage for the outbreak of World War I, the decisive inciting incident was the assassination of Archduke Franz Ferdinand and his wife, Sophie, by a radical 19-year-old Serbian nationalist student in 1914.
Part of a terrorist organization called Young Bosnia, the student, Gavrilo Princip and his cohort wanted to cede control of Bosnia and Herzegovina from the Austro-Hungarian empire which controlled it at the time. This attack forced Austria-Hungary to declare war on Serbia. Russia's support for Serbia required that they back up the country now under attack from Austria-Hungary, propelling the region into armed conflict.
Why Did the US Enter World War I?
When the war first broke out in 1914, President Woodrow Wilson promised that the United States would remain neutral throughout the conflict, a policy supported by most of the American public. However, the United States also had a close alliance with Great Britain, primarily for trade purposes.
As the conflict in Europe ensued, the United States took great issue with Germany's attempts to quarantine the British Isles. Many U.S. ships traveling to Great Britain suffered attack and destruction by German U-boats who soon declared an open attack on any vessels in the area.
In 1915, Germany attacked an ocean liner that it claimed was carrying munitions, killing nearly all 2,000 on board including more than 100 Americans. The United States warned them against attacking any non-military ships and Germany agreed to comply. In response to Germany sinking American merchant ships in 1917, the United States finally entered the conflict.
How World War I Ended
America's entrance into the war greatly shifted the conflict in the Allies favor and was a major fulcrum in the fight for victory. The United States forces were well-equipped to handle the fighting on the battlefield, and their assets were largely responsible for the Allies gaining ground in the conflict that had become exceptionally bloody. Germany formally surrendered to the Allies in 1918, and the nations achieved an Armistice while discussing the terms of future peace. In June of 1919, Germany and the Allied Nations including the United States, Great Britain, Russia, France and Italy signed the Treaty of Versailles, which was the official conclusion to the war.