What are the reasons and main features of the economic crisis in the United States?

In the 20th century, in the United States, large-scale industries were in the hands of a few corporations. Thus, all the conditions for establishing a monopoly and restricting competition were formed. Several of these corporations began to cut production. This was the reason for the drop in US production. Millions of people were out of work. Enterprises and factories were stopped. Thousands of banks have gone bankrupt because of this. It also had a negative impact on the agricultural sector, as agricultural products were not sold.