How did the US react and survive World War 1 and the interwar period (between WW1 and WW2)? Isolationism was a factor in American life during the late 1800s and early 1900s, and many people did not want to get involved in foreign wars or annex foreign territories, yet the US did both. How were Americans persuaded to do this? What events occurred in the 20 years after World War 1 and how did they impact the US?