Why in 1929 the United States was seized by the economic crisis? What were its manifestations?

In the first half of the 20th century, a deep economic crisis manifested itself in the United States. It was called the Great Depression and became a dark page in the history of the United States. There were several reasons for the start of the crisis. The external ones were that the United States participated in the First World War, the Japanese War. This weakened the country’s economy. And the key reason for the crisis was overproduction within the country. The market for goods and services was oversaturated with products, there was no one to buy it. Therefore, capital began to fall.