Two things that the Radical Republicans insisted be part of their Reconstruction plan was that the military would stay in the South to supervise the transition, and that the newly freed slaves would be offered all the freedoms of whites in the South.
Due to the fall in the stock market, there has been a decrease in consumer spending and investments. This was caused by a steep decline in industrial production and a rise in unemployment due to failed companies that fired their workers. After the fall in the first 10 months of 1930, 744 banks collapsed - 10 times more. In all, 9,000 banks collapsed during the decade of the 1930s. It is estimated that 4,000 banks failed only during one year in 1933. Until 1933, depositors lost $ 140 billion due to the failure of banks. This is too simplified to find out the decline in stock trading as a unique cause of the Great Depression. However, in 1932, when the country collapsed in the depths of the Great Depression and about 15 million people (more than 20% of the American population at that time) was unemployed.
It was built to keep the people of Berlin inside the country.
I could be wrong though.
An independent executive agency.