What was World War I?
Answer
A global conflict from 1914-1918
Explanation
World War I was a global conflict fought from 1914 to 1918 between the Allied Powers and the Central Powers, drawing in more than thirty nations and killing roughly twenty million soldiers and civilians. The war began on June 28, 1914, when a Serbian nationalist, Gavrilo Princip, assassinated Archduke Franz Ferdinand of Austria-Hungary in Sarajevo. A web of mutual defense treaties pulled the major European powers into the fighting within weeks.
The Allied Powers were led by France, the United Kingdom, and Russia, joined later by Italy in 1915 and the United States in April 1917. The Central Powers were Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria. On the Western Front, soldiers fought from a chain of trenches that ran from the English Channel to the Swiss border, and battles like the Somme in 1916 and Verdun the same year killed hundreds of thousands without moving the lines more than a few miles.
The war introduced machine guns, poison gas, tanks, submarines, and aircraft to mass combat, transforming warfare in a single generation. On the Eastern Front, Russia took staggering losses and collapsed into revolution in 1917, leading to the rise of the Soviet Union under the Bolsheviks. President Woodrow Wilson kept the United States neutral until German unrestricted submarine warfare and the Zimmermann Telegram pushed Congress to declare war on April 6, 1917.
About 4.7 million Americans served, and roughly 116,000 died. The arrival of fresh American troops in 1918 helped break the German lines, and Germany signed the armistice on November 11, 1918, the date Americans now mark as Veterans Day. The Paris Peace Conference produced the Treaty of Versailles in 1919, which forced Germany to accept blame, pay heavy reparations, and lose territory.
Four empires fell as a result of the war: the German, Austro-Hungarian, Russian, and Ottoman. New nations such as Poland, Czechoslovakia, and Yugoslavia appeared on the map. Wilson pushed for a League of Nations to prevent future wars, but the United States Senate refused to join. The unresolved grievances of Versailles and the economic hardship of the 1920s and 1930s set the stage for the rise of fascism and the outbreak of World War II two decades later.
Why this matters for your test
USCIS asks about World War I because it marks the moment the United States stepped onto the world stage as a great power, and because the war reshaped the borders, politics, and economic order of the entire twentieth century. Knowing the basic dates, sides, and outcome gives applicants the context they need for later questions about the League of Nations, World War II, and the Cold War.
Source: USCIS 128 Civics Questions (2025)
