Read Ian Kershaws biography on Hitler. This website (http://www.permanentrevolution.net/entry/2810) describes his change of fortune after the Wall Street Crash:

"Between the failed 1923 putsch and the Interior Ministry report, Germany's econo­my had stabilised to a degree. Industrial production and real wages surpassed the pre-war level for the first time in 1927. Hitler's fortunes waned. In the 1928 national Reichstag elections, the Nazis got a mere 2.6 per cent of the vote.

But the great crash on Wall Street in October 1929 irrevocably switched the points of history. Economic slump engulfed the capitalist world over the next four years. In January 1930, German unemploy­ment reached over 4.5 million: wages, out­put and prices began a steep fall uninter­rupted until mid-1932. Workers were thrown onto the scrap heap; the middle classes were ruined" etc etc