Why was the American Depression of 1929 so sudden and so severe?

In what regards the depression, the main reason was 'The Wall Street Crash'. In the 1920s the stock market shares went skyrocketing at an incredible and alarming rate therefore people could speculate their rise and make fortunes out of this. Ironically it was speculation itself what brought 'The Wall Street Crash' upon the American people. In Thursday, October 24, also known as 'Black Thursday' 12,894,650 shares changed hands, many of them at such low prices that destroyed any dream or future that the people who had owned them had optimistically thought of. By 11:30 AM the market had turned into a wild rush to sell, people were running around in panic trying to recuperate at least some of their money, the Police had to keep their eyes wide open in case any tragedy would happen. Eleven well-known speculators had already killed themselves. This happened in only one day, in which historians now recognize as the awakening of the great depression (though not its beginning, which has been thought to have started a while before).

The impact that the Wall Street Crash had caused upon the American people was severe. The rate of unemployment was incredibly high, higher than ever before. By 1932 America was in the greatest depression of its history, the economy had reached the bottom, approximately 13 million Americans were unemployed, 'No Men Wanted' signs appeared in factories and businesses across the country, 5,000 banks had gone out of business since 1929 consequently at least 10 million people had lost their savings, some children did not even have no clothing, no shoes, and no food. The 'Roaring Twenties' now remained in the distant past.

To conclude, in my opinion the Wall Street Crash was the main reason for the depression even though there were so many others such as the 'Florida Land Boom' which left some people with property wildly over priced, that had low values before. Industrial production of consumer goods reached too high a level. There was a lot of investment being made in the stock market, but workers' wages remained low, so market for consumer goods was small and supply of goods surpassed demand, as an example there were too many cars being made, and not too many people who could afford to buy them. In other words all the other reason did take their part, but none were as severe and chaotic as the Wall Street Crash, main reason for the depression, and vanquisher of the dreams of millions of Americans.

Side Note: Most of this information was derived from the USA history textbook by John Traynor.