What exactly caused the Great Depression and what are the most important dates?

There were numerous elements that led to the Great
Depression. The Stock Market Crash of October 29, 1929 was symptomatic of the problems
leading to the depression but was not per se the cause of the depression.  Among the
causes:

Businesses had tried to maintain prices and take
profits while holding wages down. The end result was that one third of personal income
went to 5 % of the population. Profits were put into expansion rather than wages,
businesses created an imbalance between productivity and purchasing power. They never
made the connection.

Governmental policies didn’t help.
Secretary of the Treasury Andrew Mellon’s tax policies encouraged over-saving, which
diminished the demand for consumer goods. This extra money in the money supply
encouraged speculation. Much of that overspeculation was in the Stock market and real
estate.There were signs in the air that things were about to come to a screeching halt.
Residential construction and automobile production were catching up with demand. There
were no more people standing in line to buy them. Business inventories began to rise
because there were not that many customers; and consumer spending began to slacken off.
All these are signs of a slowing economy, but the speculators in the stock market
ignored the signs, and continued to buy, buy, buy, and as a result, the market continued
to rise.

The gold standard was another problem. Keeping
money tied to gold kept the money supply tight, and made the economy worse. The only way
that the economy could stabilize under the gold standard was to allow prices and wages
to fall until they reached a point where they were stable. Needless to say, it would
wipe out a lot of people on the way down.

By 1929, the
market had gotten so high it was a fantasy world, everybody knew it was overpriced, but
it didn’t stop. Financial experts who argued that things should slow down were ignored.
Hoover was worried, and told the Federal Reserve to discourage speculation. As a result,
the Fed raised the discount rate, the amount it loaned to member banks, thereby making
it more expensive to borrow money, but it had no effect.

By
Fall of 1929, the stock market began to fluctuate; it was beginning to show signs of
uneasiness. Finally, investors got worried, and were afraid prices could go no further,
and started unloading shares. This, of course, drove prices down. The market staggered
for a few days until Tuesday, October 29, 1929, (Black Tuesday); the bottom fell out,
with sellers dumping stock wildly. The end result was the most disastrous day in Wall
Street history. A busy day for the market then was three million shares. On that day,
16.4 million shares were traded.

The decline in the stock
market and slowdown in the economy caused consumers and business people to hold out for
lower prices. As a result, prices fell, but at the same time wages fell, and business
dropped drastically. From 1929 – 1932, American’s personal incomes fell by more than
half. More than 9,000 banks closed; hundreds of factories and mines shut down, thousands
of farms were sold at foreclosure