(warning: twitter pedantry to follow...)
![](https://pbs.twimg.com/media/D5QPfOpXsAAuF_h.png)
afam.nts.jhu.edu/people/lewis/l…
(three cheers for undergrad research!)
and also this oral history with Broadus Mitchell, where you can actually hear him discuss this:
docsouth.unc.edu/sohp/B-0024/me…
press.uchicago.edu/ucp/books/book…