I’ve had occasion in the past to reference the Melungeons, “tri-racial isolates” of the southern US. Reports of these groups, and others such as the “Tribe of Ben Ishmael,” made up an important part of the eugenics literature of the late 19th century. Some important pieces of that literature are available on the website of the Melungeon Heritage Association. (Check out the left navigation menu or click on “Tools for Research. Thanks to Terry from the Left Libertarian list for the heads-up.)
