USA

The US declared war on Germany in April 1917, more than two and a half years after WWI started. 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. The U.S. made its major contributions in terms of supplies, raw material and money, starting in 1917. American soldiers started to arrive at a rate of 10,000 men per day on the Western Front in the summer of 1918. 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.