The Great Depression was an economic crisis started in 1929 and continued for next several next years. It began in the United States of America after the stock market crash. The main cause behind it was the fall of aggregate demand due to under consumption and over investment. The output and employment levels in the countries of Europe and North America fall by huge amounts. It affected the whole world. The demand of the goods in the market during this period was very low so production was also lowered which lead to unemployment. In I-ISA, from 1929 to 1933, unemployment rate rose from 3 percent to 25 percent.