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  Gavrilo Princip assassinated the Archduke, leading to the first World War.
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  After the assassination of their Archduke, Austria-Hungary declared war on Serbia.
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  Germany invaded Belgium
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  Germany begins to block Great Britain's naval ships from being able to trade.
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  Italy declared war on Austria-Hungary, switching sides in the war.
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  The Bloodiest battle of the Civil War
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  The US joins the war by declaring war on Germany.
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  Russia signed an armistice which marked them leaving the war.
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  Germany signs the Armistice at Compiègne, ending World War I.
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  The war officially ended, with the Treaty of Versailles taking effect.