Emperor Franz Joseph of Austria-Hungary declares war on Serbia.
As an ally of Serbia, Russia announces full mobilization of her armed forces
Germany mobilizes her armed forces and declares war on Russia
Germany declares war on France
Austria-Hungary declares war on Russia
First trenches of the Western front are dug
First Battle of the Marne halts German invasion in France
War becomes "Total War" with German Zeppelin air raid on England
Germany declares a submarine blockade of Great Britain
Allies begin nine-month battle for the Turkish peninsula of Gallipoli
U-boat sinks the Lusitania. 1,198 civilians, including 128 Americans die
Germany responds to U.S. anger by ceasing to sink ships without warning
Allies begin withdrawal of troops from Gallipoli
The longest battle of the war, the Battle of Verdun, is fought to a draw with an estimated one million casualties
US President Wilson publicly warns Germany not to continue unrestricted submarine warfare policies
The Battle of the Somme results in an estimated one million casualties and no breakthrough for the Allies. British introduce the tank, an effective weapon but far to few to make much of a difference
The Battle of the Somme ends
Battle of Verdun ends
Reich Foreign Secretary Zimmermann's telegram to Mexico urging her entry into war against the United States is discovered and translated by the British
Germany again declares unrestricted submarine warfare
President Wilson asks Congress for a declaration of war with Imperial Germany
The first wave of the American Expeditionary Force lands in France
American troops in France fire their first shot in trench warfare
The new Russian government, represented by Leon Trotsky, signs an armistice with Germany
President Woodrow Wilson declares his 14 points as the path to permanent world peace
Germans launch the first of five major offensives to win the war
Allied counter offensives on the Somme push the German army back and into retreat
Turks sign armistice
A German republic is founded
At eleven o'clock on the eleventh day of the eleventh month of 1918, the war ends as Germany and Allies sign an Armistice
Peace Treaty signed by German delegates and Allies in Versailles
The United States Senate fails to ratify the Treaty of Versailles and U.S. involvement in the League of Nations
The 19th Amendment to the U.S. Constitution, which gave women the legal right to vote, was ratified
