No. It was mostly from old Joe manipulating Wall Street with tactics that would send you to jail for 100 years today. But that was before there was an SEC. Then he got into Hollywood early (mostly so he could screw young starlets) and added more to his fortune there by laundering profits. He then bought some oil companies which the family trust still owns.
None of his kids or grandkids have ever had to work for a living.
Another thing he did while Ambassador to the U.K. was to actively preach against the U.S. entering the war - he said that democracy was over and the free world couldn't win - sound familar?!