This is the published version of my JBHE (Journal of Blacks in Higher Education) paper. Much of what I wrote was incompatible with JBHE's space requirements and vanished in author-editor negotiations over length. More important, JBHE is not a journal that goes in for citing of sources. (Much of what I write comes from primary sources. What I write about Amherst's Anti-Slavery Society comes almost entirely from Robert Brigham's excellent undergraduate thesis.) I also had to leave out discussion of such important matters as the uncertainties in my number for the enslaved population of Deerfield's main street in 1752. In scientific talk, I would say 21 +/- 3, by which I mean that if the true result were anywhere in the range, roughly, from 18 to 24, I would hardly be astonished. I am quite certain that "about 21" is a correct statment. I also had to omit my map, my 1752 "snapshot", but the article does point the reader to this website. The map is available here, and the JBHE article here.