United States in World War I

The United States declared war on the German Empire on April 6, 1917, during World War I. The U.S. was an independent power and did not officially join the Allies. It closely cooperated with them militarily but acted alone in diplomacy. The U.S. made its major contributions in terms of supplies, raw material and money, starting in 1917. American soldiers under General John Pershing, Commander-in-Chief (C-in-C) of the American Expeditionary Force (AEF), arrived in large numbers on the Western Front in the summer of 1918. They played a major role until victory was achieved on November 11, 1918 at 11:00am. Before entering the war, the U.S. had remained neutral, though it had been an important supplier to Great Britain and the other Allied powers. During the war, the U.S. mobilized over 4 million military personnel and suffered 110,000 deaths, including 43,000 due to the influenza pandemic. The war saw a dramatic expansion of the United States government in an effort to harness the war effort and a significant increase in the size of the U.S. Armed Forces. After a relatively slow start in mobilizing the economy and labour force, by spring 1918 the nation was poised to play a role in the conflict. Under the leadership of President Woodrow Wilson, the war represented the climax of the Progressive Era as it sought to bring reform and democracy to the world, although there was substantial public opposition to U.S. entry into the war.

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