What part did the us take in ww1?

Answer 1

The entrance of the United States into World War One essentially won the war for the Allied Powers (Britain, France and Russia; plus Italy later). The Americans entered the war after Germany declared the policy of unrestricted submarine warfare, which meant that any boats in neutral territory could be attacked by German u-boats. After a series of American casualties resulting from these German attacks, the "dough boys" entered the war.