The stock market crash triggered the beginning of the Great Depression the worst economic crisis in U. S history (which factor did not contribute to the crash)

Stock market crash of 1929, also called the Great Crash, a sharp decline in U.S. stock market values in 1929 that contributed to the Great Depression of the 1930s. The Great Depression lasted approximately 10 years and affected both industrialized and nonindustrialized countries in many parts of the world.

these civilizations were located around fertile rivers, where they could produce an abundance of crops