Causes of the Great Depression

In class today, we had a long discussion about the causes of the Great Depression. The Great Depression lasted for the duration of around 1929-1939. There was not one specific event that caused the Great Depression, but rather an accumulation of different declines in many different aspects of the economy which caused a chain reaction and allowed for no way to fix it.

For example, one reason that we discussed was lack of diversification in the American Economy. The economy following the 20's was largely based on only two industries, construction and manufacturing. Because of this lack of diversification, if one industry begins to fail, which they did, then it would cause all others to fail with nothing strong enough to counter it. A large part of manufacturing was the automobile, but after a certain point sales declined because everyone who needed or wanted one already had one. Also, construction was not always reliable because it was hard to predict whether a city would need a skyscraper built or not. Another industry, agriculture, was terribly failing after the end of WWI leaving it with a much smaller number of consumers.

With these industries failing, it causes people to be laid off and for there to be less jobs. This makes the poor, working class even more poor and a lot more people were in poverty. With people in poverty, they could not buy things that helped fuel the economy and continue the circulation of money. It was a vicious cycle that could not be lifted.

Trade declining during this time with other countries also isolated the Americans even more and there was nothing to save them. Tariffs caused international trade to be too expensive and to have no consumers willing to buy.

Is there anything the Americans could have done to prevent the Great Depression, or reduce its length? Are there any other causes or effects that you guys want to add?