Why did russia withdraw from world war i early, and why did the united states enter late?

In 1917 they wanted To negotiate a treaty and Germany wanted independence so Russia was holding it out until 1918 and the fighting resumed in the Eastern front I dont know about the u.s tho sorry

united states reinforcements contributed greatly to three allied victories in france at: cantigny (first major american battle), argonne (the largest in the united states military history, involving 1.2 million american soldiers), and château-thierry (one of the first actions under general pershing).

“the iliad” (gr: “iliás”) is an epic poem by the ancient greek poet homer, which recounts some of the significant events of the final weeks of the trojan war and the greek siege of the city of troy (which was also known as ilion, ilios or ilium in ancient times).