Final answer:
The dramatic increase in unemployment before 1930 was primarily a result of the 1929 stock market crash, which triggered the Great Depression.
Step-by-step explanation:
The dramatic increase in unemployment shortly before 1930 is a result of the 1929 stock market crash. This event set off what would become the Great Depression, an economic downturn that saw widespread bank failures, severe deflation, and a dramatic rise in joblessness. It was during this difficult time that over 15 million workers became unemployed and the national unemployment rate soared to 25%. While other factors such as the Dust Bowl and factory underproduction also worsened the economic situation, it was the stock market crash that precipitated the initial collapse. Notably, the election of Franklin D. Roosevelt and his subsequent New Deal helped provide relief and attempted to rejuvenate the economy by creating programs like the Works Progress Administration (WPA).