This 1914 German plan aimed to avoid a two-front war by defeating France quickly before fighting Russia.
Schlieffen Plan
This weapon, first used by Germans at the 2nd Battle of Ypres, was eventually surpassed by a "persistent" mustard variety.
Chlorine gas
This U.S. President led the country through the duration of World War I
Woodrow Wilson
This specific clause in the Treaty of Versailles forced Germany to accept total responsibility for the war.
War Guilt Clause
This term describes the act of assembling and preparing a nation's troops for war
Mobilize
This 1914 battle effectively ended mobile warfare and led to the transition into trench warfare.
Battle of the Marne
These small, fast-moving squads used infiltration tactics to bypass enemy strongpoints
Stormtrooper tactics
This 1917 Act created the national military draft in the United States.
Selective Service Act
Under the Treaty of Versailles, the German army was restricted to this specific number of soldiers
100,000
This is the specific term for the dangerous, unoccupied land located between opposing trenches.
No Man's Land
This battle is considered the bloodiest in British history, with 60,000 casualties on the first day alone.
Battle of the Somme
Germany used these "__________" to attack ships in war zones without warning, a practice known as "unrestricted" warfare.
U-Boats
In this intercepted telegram, Germany promised to help Mexico recover Texas, New Mexico, and Arizona.
Zimmermann Telegram
Germany was ordered to pay this massive total amount in reparations to help rebuild other countries.
33 billion
This term refers to a piece of territory, like the one at Ypres, that pushes deep into enemy lines.
Salient
This battle was intended by the Germans to "bleed France white" and became a symbol of French national pride
Battle of Verdun
This British intelligence group was responsible for intercepting and decoding enemy communications.
Room 40
This was the nickname given to U.S. Marines by German soldiers during the war.
Devil Dogs
This was the primary international organization created by the Treaty of Versailles to promote cooperation
League of Nations
This is an agreement made by opposing sides in a war to stop fighting, often a precursor to a peace treaty.
Armistice
The "Hundred Days Offensive" began on August 8, 1918, with this battle, known as the German army's "Black Day"
Battle of Amiens
This naval engagement in the North Sea involved over 250 ships and 100,000 sailors.
Battle of Jutland
This British passenger ship was sunk by a U-Boat in 1915, greatly angering the American public.
Lusitania
The harsh terms of the Treaty of Versailles led to this specific economic crisis in Germany in 1923.
Hyperinflation
This term describes a nation's state of not supporting or helping either side in a conflict
Neutrality