What is the claim (thesis statement) in the cause and effect essay? introductory paragraph the great depression was the worst economic event in u. s. history. it completely changed the life of every american. it began in 1929 with the greatest stock market crash ever experienced and continued for about ten years. as a result of the depression, the government took a stronger, more powerful role in regulating the nation’s economy. a. the great depression was the worst economic event in u. s. history. b. it completely changed the life of every american. c. it began in 1929 with the greatest stock market crash ever experienced and continued for about ten years. as a result of the depression, the government took a stronger, more powerful role in regulating the nation’s economy.