Excerpts from Books and Wikipedia
"Speculation had led to a massive inflation in the price of shares that bore little relation to the companies they represented. This did not seem to matter while confidence was high and people were buying, but once confidence sank, there was a massive and infectious panic to sell. The Wall Street Crash resulted in depression and unemployment in the United States followed by Roosevelt's New Deal from 1933. In Europe, the consequences were even more severe. As US loans were recalled and the US market for European exports disappeared, fragile democracies collapsed and the era of Nazism, fascism, and war began." [Furtado: 1001 Days] "Thus the young U.S.S.R. was necessarily launched on a course of self-contained development, in virtual isolation from the rest of the world economy. Paradoxically this was soon to provide it with its most powerful ideological argument. It seemed immune to the gigantic economic depression which devastated the capitalist economy after the Wall Street crash of 1929." [Hobsbawm: Extremes, p. 375]