The Great Depression

Nine of the ten plagues of exodus are eerily similar to things that actually occur in egypt as part, on a fairly regular basis, as part of its agricultural cycle. They seem like exaggerated versions of things that normally happen. And for a pharaoh who eves in the existence of gods that are controlling nature, if a bunch of abnormally strong natural events start happening, when you've got a prophet there interpreting them for you, this way you could be convinced. So i don't think we should dismiss this.