Which event helped end the Great Depression in the United States?

The end of World War I in 1918 did not directly contribute to the end of the Great Depression, which began in 1929. While the post-war period experienced some economic growth, it was followed by the Roaring Twenties' boom and subsequent bust, leading to the financial crisis of the Great Depression. Thus, the end of WWI is unrelated to the economic recovery in the 1930s.

The baby boom, which occurred after WWII, contributed to economic growth in the 1950s and 1960s but did not play a role in ending the Great Depression. This demographic shift followed the war, benefiting from the economic recovery initiated by wartime production. Therefore, it cannot be credited with influencing the conditions of the 1930s.

Nuclear technology and its development came about during and after WWII, primarily as part of the war effort and later for energy purposes. While it had significant implications for post-war America, it was not a factor in ending the Great Depression, which was primarily influenced by wartime economic changes rather than technological advancements.