Explanation:
The United States declared war on Germany on April 6, 1917, nearly three years after World War I started. A ceasefire and Armistice was declared on November 11, 1918. Before entering the war, the U.S. had remained neutral, though it had been an important supplier to the United Kingdom, France, and the other Allied powers.
The U.S. made its major contributions in terms of supplies, raw material, and money, starting in 1917. American soldiers under General of the Armies John Pershing, Commander-in-Chief of the American Expeditionary Force (AEF), arrived at the rate of 10,000 men a day on the Western Front in the summer of 1918. During the war the U.S. mobilized over 4 million military personnel and suffered 110,000 deaths, including around 45,000 who died due to the 1918 Spanish influenza outbreak (30,000 before they even reached France).[1][2] 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. Â 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 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. The American entry into World War I came on April 6, 1917, after a year long effort by President Woodrow Wilson to get the United States into the war. Apart from an Anglophile element urging early support for the British, American public opinion sentiment for neutrality was particularly strong among Irish Americans, German Americans and Scandinavian Americans,[3] as well as among church leaders and among women in general. On the other hand, even before World War I had broken out, American opinion had been more negative toward Germany than towards any other country in Europe.[4] Over time, especially after reports of atrocities in Belgium in 1914 and following the sinking of the passenger liner RMS Lusitania in 1915, the American people increasingly came to see Germany as the aggressor.
In 1912 Woodrow Wilson was elected President of the United States. Wilson successfully kept Americans troops out of World War I during his first term. However American involvement became inevitable later on in World War I.  As the European powers squared off in 1914 in what was to be four years of mind-numbingly horrific war, America managed to somewhat nervously mind its own business. Wilson, in fact, won reelection in 1916 using the phrase “he kept us out of war.”Propagandistic portrayals of German atrocities in the relatively new medium of motion pictures added to the heat. And finally, when it was revealed that German diplomats had approached Mexico about an alliance against the United States, Wilson felt compelled to ask Congress for a resolution of war against Germany. He got it on April 6, 1917.
The U.S. military was ill-prepared for war on a massive scale. Only about 370,000 men were in the Army and National Guard combined. Through a draft and enlistments, however, that number swelled to 4.8 million in all the military branches by the end of World War I.
At home, about half of the war’s eventual $33 billion price tag was met through taxes; the rest was funded through the issuance of war bonds. Organized labor, in return for concessions such as the right to collective bargaining, agreed to reduce the number of strikes.
