Ties and treaties bound countries to assist each other in time of war. When the time came, they started choosing sides. The United States declared neutrality until German submarine warfare threatened American commercial shipping.
The Central Powers consisted of Austria-Hungary, Bulgaria, Germany, and Ottoman Empire (now Turkey).
The Allied Powers consisted of Belgium, France, Great Britain, Greece, Italy, Montenegro, Portugal, Romania, Russia
, Serbia and the United States.
US Troop Statistics:
(Source: Defense Casualty Analysis System
Battle deaths: 53,402
Non-battle deaths: 63,114
Total deaths: 116,516
Total US soldiers wounded: 204,002
Total number of US troops that served in the conflict: 4,734,991
Other Military Casualties by Country:
(Source: Encyclopedia Britannica
1,200,000 dead; 3,620,000 woundedBelgium:
13,716 dead; 44,686 woundedBulgaria:
87,500 dead; 152,390 woundedFrance:
1,357,800 dead; 4,266,000 wounded
1,773,700 dead; 4,216,058 woundedGreat Britain:
908,371 dead; 2,090,212 wounded
5,000 dead; 21,000 woundedItaly:
650,000 dead; 947,000 wounded Japan:
300 dead; 907 woundedMontenegro:
3,000 dead; 10,000 woundedOttoman Empire (Turkey):
325,000 dead; 400,000 woundedPortugal:
7,222 dead; 13,751 woundedRomania:
335,706 dead; 120,000 wounded
1,700,000 dead; 4,950,000 wounded
45,000 dead; 133,148 woundedGrand total (including US):
8,528,831 dead; 21,189,154 wounded
June 28, 1914 - Gavrilo Princip, who has ties to the Serbian terrorist-type group the Black Hand, assassinates Archduke Franz Ferdinand of Austria-Hungary.
July 28, 1914 - Austria-Hungary declares war on Serbia.
August 1, 1914 - Germany declares war on Russia.
August 2, 1914 -
Ottoman Empire (Turkey) and Germany sign a secret treaty of alliance
August 4, 1914 - Germany invades Belgium. President Woodrow Wilson declares that the United States is neutral. Britain declares war on Germany.
August 10, 1914 - Austria-Hungary invades Russia, opening the fighting on the Eastern Front.
August 26-30, 1914 - Battle of Tannenberg, Prussia.
September 12, 1914 - First battle of the Aisne in France, begins, marking the beginning of trench warfare.
November 3, 1914 - Russia declares war on Ottoman Empire (now Turkey).
November 5, 1914 - Great Britain and France declare war on Ottoman Empire.
April 22-May 25, 1915 - Second Battle of Ypres, marking the first wide-scale use of poison gas by Germany.
May 7, 1915 - A German U-20 submarine sinks the British passenger ship, the Lusitania; 1,198 are killed, including 128 Americans.
June 1915-November 1917 - Battles of the Isonzo, Italy.
1915 - Battle of Krithia, Gallipoli peninsula, Ottoman Empire.
February 21-July 1916 - Battle of Verdun, France, the war's longest battle, with almost a million casualties.
May 31-June 1, 1916 - Battle of Jutland, North Sea near Denmark - a sea battle between British and German navies.
July 1, 1916-November 1916 - First Battle of the Somme River, France. The British introduce the tank.
April 6, 1917 -
The United States declares war against Germany after the interception and publication of the Zimmermann Telegram
and the sinking of three US merchant ships
by German U-boats.
June 26, 1917 - American troops begin landing in France.
November 20, 1917 - Battle of Cambrai, France.
December 3, 1917 - Russia signs an armistice with Germany.
March 3, 1918 - Russia signs the Treaty of Brest-Litovsk, ending hostilities with the Central Powers and withdrawing Russia from this war.
March 21-April 5, 1918 - Second Battle of the Somme River.
September 29, 1918 - Bulgaria signs an armistice.
October 30, 1918 - Ottoman Empire (Turkey) signs an armistice.
November 3, 1918 - Austria-Hungary signs an armistice.
November 11, 1918 - Germany accepts the armistice terms demanded by the Allies, ending the war.
June 28, 1919 -
The Treaty of Versailles is signed at the Palace of Versailles