The United States<span> declared war on </span>Germany<span> on April 6, 1917, during </span>World War I<span>. The U.S. was an independent power and did not officially join the </span>Allies<span>. It closely cooperated with the Allies 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 </span>General John Pershing<span>, </span>Commander-in-Chief<span> (C-in-C) of the </span>American Expeditionary Force<span> (AEF), arrived in large numbers on the </span>Western Front<span> in the summer of 1918. Before entering the war, the U.S. had remained neutral, though it had been an important supplier to </span>Great Britain<span>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 </span>influenza pandemic.[1]<span> The war saw a dramatic expansion of the </span>United States government<span> in an effort to harness the </span>war effort<span> and a significant increase in the size of the </span>U.S. Armed Forces<span>. After a relatively slow start in mobilizing the economy and labor force, by spring 1918, the nation was poised to play a role in the conflict. Under the leadership of </span>President Woodrow Wilson<span>, the war represented the climax of the </span>Progressive Era<span> as it sought to bring reform and democracy to the world, although there was substantial public opposition to U.S. entry into the war.</span>
The Battle of Fort Sumter (April 12–13, 1861) was the bombardment of Fort Sumter near Charleston, South Carolina by the South Carolina militia (the Confederate Army did not yet exist), and the return gunfire and subsequent surrender by the United States Army, that started the American Civil War.