Answer :
The answer is Britain and France. Before entering the war, the U.S. had stayed unbiased, however it had been a critical provider to Great Britain and the other Allied forces. Amid the war, the U.S. activated more than 4 million military faculty and endured 110,000 passings, including 43,000 because of the flu pandemic.
During the war, even though the United States wanted to remain neutral, they supported Britain and France. As such an ally the United States made its major contributions in terms of supplies, raw material and money, starting in 1917. Of course, officially it was an independent power.