Tanks were used for the first time in battle, at the Battle of the Somme, during World War I.
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The US declared war against Germany and its Central Powers Alliance in World War I.
The First Battle of the Marne began during World War I.
Dutch exotic dancer Mata Hari was put on trial in Paris after being accused of being a spy.
During World War I, as a soldier, Adolf Hitler was injured by a grenade blast.
During World War I, Japan officially declared war on Germany.
