America's involvement in World War II had a significant impact on the economy and workforce of the United States. The United States was still recovering from the impact of the Great Depression and the unemployment rate was hovering around 25%. Our involvement in the war soon changed that rate.
The Truman Doctrine was the event that triggered off the Cold War.
Explanation: Both parties were mutually hostile and did not believe in a possible peaceful coexistence anymore. The Americans and Soviets’ hostility to each other as well as the belief that they could no longer cooperate after the start of the Cold War resulted in the Berlin Blockade. Thus, I can conclude that the Truman Doctrine marked the start of the Cold War.
Yes, it was the Boxer Rebellion. :))