-
his death in Sarajevo by a Serbian nationalist caused Austria-Hungary to issue an ultimatum to Serbia, leading to a declaration of war -
The US maintained neutrality in World War I at the start, under President Woodrow Wilson, who urged Americans to be impartial in thought and deed -
The First Battle of the Marne, fought in September 1914, was a decisive Allied victory that halted the German advance on Paris and ended Germany's hopes for a quick victory in World War I -
The sinking of the Lusitania occurred on May 7, 1915, when a German U-boat torpedoed the British ocean liner without warning off the coast of Ireland. The ship sank in less than 20 minutes, killing 1,198 people, including 128 Americans, causing outrage in the United States and contributing to its later entry into World War I -
The Battle of Verdun was a prolonged and devastating WWI engagement in 1916 where the German army attempted to capture the French fortress city of Verdun but was repulsed by the French -
The "Sussex incident" was the torpedoing of a French passenger steamer, the SS Sussex, by a German submarine in the English Channel on March 24, 1916. The attack, which occurred without warning, resulted in approximately 80 casualties, including two Americans wounded. This act of aggression led the United States to threaten to sever diplomatic relations, prompting Germany to issue the Sussex Pledge. -
The Battle of the Somme was a major offensive by Allied forces (British Empire and France) against the German Empire along the Somme River in France from July to November 1916, during World War I -
The Zimmermann Telegram was a secret diplomatic communication sent by Germany to Mexico in January 1917 proposing a military alliance against the United States during World War I. It promised Mexico financial support and the recovery of territories in Texas, New Mexico, and Arizona if the U.S. entered the war -
German unrestricted submarine warfare was a naval tactic in World War I and World War II where submarines, or U-boats, attacked enemy and neutral merchant ships without warning. Germany used this strategy to cut off enemy supplies and economies, particularly the British blockade, and it ultimately led to the United States entering World War I -
The United States entered World War I on April 6, 1917, after President Woodrow Wilson asked Congress for a declaration of war against Germany. The primary causes were Germany's policy of unrestricted submarine warfare and the Zimmermann Telegram, which proposed a German-Mexican alliance against the U.S -
The Selective Service Act is a federal law that created the Selective Service System, which provides a way to raise an army through conscription, or compulsory military service. -
The Espionage Act is a 1917 United States federal law that makes it a crime to interfere with the war effort, steal, or improperly share information related to national defense -
The American Expeditionary Forces (AEF) in France was the United States Army's formation in World War I, led by General John J. Pershing. The AEF fought alongside the French and British on the Western Front, playing a critical role in the final offensives of the war and turning the tide against the Central Powers with fresh troops and resources. Its major engagements included the Aisne Offensive, Battle of Saint-Mihiel, and the Meuse-Argonne Offensive. -
President Wilson's Fourteen Points were a set of principles for peace presented in a 1918 speech to end World War I, emphasizing open diplomacy, free trade, disarmament, and self-determination for nations. -
The Spanish Flu was a devastating influenza pandemic from 1918-1919, caused by an H1N1 virus, which infected about one-third of the world's population and killed 50 to 100 million people -
Russia withdrew from World War I in March 1918 by signing the Treaty of Brest-Litovsk with the Central Powers, ending its participation in the conflict. This decision was driven by the Russian Revolution, which brought the Bolsheviks to power and led them to prioritize domestic issues over the war, a move that resulted in significant territorial losses for Russia. -
The Sedition Act refers to two key laws: one from 1798 and another from 1918, both of which restricted speech that was critical of the government -
The Battle of Argonne Forest, part of the larger Meuse-Argonne Offensive, was a major World War I battle fought by the American Expeditionary Forces against German forces from September 26 to November 11, 1918. It was the deadliest battle in American military history, characterized by brutal trench warfare, difficult terrain in the dense forest, and fierce German resistance -
Armistice Day, on November 11, 1918, marked the end of fighting in World War I when Germany and the Allied powers signed a ceasefire agreement in a railway car in Compiègne, France. The armistice went into effect at 11 a.m. Paris time, the "eleventh hour of the eleventh day of the eleventh month". While it ended the hostilities, a formal peace treaty, the Treaty of Versailles, was not finalized until months later. -
The Paris Peace Conference convened in 1919 to establish peace after World War I, leading to several treaties, the most significant being the Treaty of Versailles with Germany