I don't know if this has been discussed here before but I find it pretty amazing that I've never heard of it until now. The gist of it is that business owners were fearful of FDR's socialist plans to get us out of the depression, and thought fascism would do the trick so they approached Marine Corps Major General Smedley Butler to help overthrow FDR in a coup. Butler exposed this plot, and FDR more or less forgave them if they agreed to stay out of his way and let him do what he wanted. Interesting tidbits are that Prescott Bush was involved, and JP Morgan would have faced the death penalty
original BBC radio broadcast in mp3 format:
someone added visuals to it:
wiki on business plot:
wiki on Smedley Butler:
prisonplanet article w/ anti Bush slant:

I thought this quote from wiki on Butler is worth mentioning:
In addition to his military career, Smedley Butler was noted for his outspoken anti-interventionist views, and his book War is a Racket. His book was one of the first works describing the workings of the military-industrial complex and after retiring from service, he became a popular speaker at meetings organized by veterans, pacifists and church groups in the 1930s.