Although this documentary brings together a lot of interesting footage, lack of a commentary means that a viewer without a close knowledge of the period in question will find themselves wondering, "Who were those people, and why was what they were doing of historical significance?" On the other hand, if you are very familiar with the politics and culture of the US in the 1930s, this may provide some useful illustrative imagery. I suspect that, these days, more people will fall into the first category.