Answer:
The date the United States entered the war = On April 6, 1917
The date of Treaty of Versailles = 28 June 1919
Step-by-step explanation:
USA started fighting for it allies ( Britain, France, and Russia ) on April 6, 1917.
Over 2 million USA soldiers fought on the battle fields. US citizens were not in favour of entering the war. The date of the Treaty of Versailles is 28 June 1919 and it is the most important of the peace treaties that brought World War I to an end.