The great depression didn't just affect America, it sent the world into a frenzy. Not to mention the Germans were unjustly treated. Their homes were taken and partitioned to different, new countries. They were broke already as all their money was taken, their military was shut down, and don't get me started and the food shortages. Inflation was high enough in Germany and the great depression just made the Germans even more desperate for something they could grasp on to, a small glimpse of a bright future. Hitler was their answer but soon after they got out of that mess not all Germans agreed with hitler's Third Reich.
So the take away is not all Germans in WW2 were Nazis and being broke does crazy things to people.
Steam-driven ships allowed Europeans to reach distant Asian, African, and Pacific ports more quickly and predictably and to penetrate interior rivers as well.
