African-American heritage of presidents of the United States
Calvin Coolidge's mother Victoria Moor was claimed to be of a mixed-race family in Vermont. Vaughn noted that her surname was derived from "Moor", a European term for people of North Africa. He did not note that another meaning of her surname is the landscape feature of moor or bog. People's surnames were often based on such landscape features when surnames became generally adopted in 14th century England. Moor/Moore is a common name in England, Scotland, and Ireland.
Moors
Some Muslims converted to Christianity and remained permanently in Iberia. This is indicated by a "high mean proportion of ancestry from North African (10.6%)" that "attests to a high level of religious conversion (whether voluntary or enforced), driven by historical episodes of social and religious intolerance, that ultimately led to the integration of descendants." According to historian Richard A. Fletcher, "the number of Arabs who settled in Iberia was very small. 'Moorish' Iberia does at least have the merit of reminding us that the bulk of the invaders and settlers were Moors, i.e., Berbers from Algeria and Morocco."