> When do you think The Great Depression was?
The GD was a worldwide phenomenon - so effects were felt at somewhat different times and in different places depending on where you were.
In the USA many believe it was kicked off by the Panic of '29, though it took awhile before the real damage to the broader economy became apparent and the politicians actually got off their asses and made real policy moves[1]. So, if I had to pick a range, I'd say ~1930-1940, though one can quibble a year or two.
If you're interested in first-hand accounts of the Depression and the creeping-damage done, I'd suggest http://www.amazon.com/Great-Depression-Diary-Benjamin-Roth/dp/158648799X. It's on audible.com as well.
[1] I'm certainly not suggesting the moves they made were "right," and in fact until I really started reading I had no idea how draconian some of FDR's moves under the NRA were (price fixing, gold confiscation, et al). In any event it's interesting to read contemporary reports of their implementation.