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  The United States declared to reamin neutral.
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  A German U-boat torpedoed and sank the RMS Lusitania.
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  The Sussex Pledge was a promise made in 1916 during World War I by Germany to the United States.
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  The Zimmermann Telegram was a diplomatic proposal from the German Empire, for Mexico to join an alliance with Germany in the event of the United States entering World War I against Germany. The proposal was intercepted and decoded by British intelligence.
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  Germany thought they could beat the Allied Forces by taking submarine warfare before the United States could enter the war.
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  United States Merchant Ships, Sailing Vessels, and Fishing Craft Lost from all Causes during World War I.
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  President Woodrow Wilson went before a joint session of Congress to request a declaration of war against Germany.