Raghuram Rajan breaks down some of the channels through which these two concepts are related, including some history, in this Project Syndicate piece.
A more nuanced view with more interesting implications (and great accompanying style!) by David Harvey is here.
Other Marxist interpretations with an emphasis on inequality are those of Rick Wolff and David Kotz.
And actually, I had a student in my American Economic History class who wrote an amazing paper on how inequality is related to the Great Crash of 1929. I think he reads this blog too -- Rob V., feel free to offer comments on your view of this! I believe he used Kindleberger, an article by Eugene White on the Crash, and possibly even Lichtenstein's State of the Union.