Like boots and shoes and clothes and pots?

Those are all directly applicable items of need - as opposed to headphones and phones and laptops and (name electronic product)...

So what items were a glut in ~1930 that would have contributed to this?

My skepticism tells me it was financial speculation, and not physical goods that had more an impact.

And even if I were correct, which I do not know, I'm amazed that there was enough thought in the space to create such a depression.

The phrase "money is the root of all evil" only exists for a reason...