There must have been a sizable diaspora of the Jewish people from Spain about that time. A number of them fled to Germany and Ireland, and from there to the New World, to avoid persecution.
There is some evidence that the Mellungeon people of Appalachia are descended from these Mediterranean Jewish (Sephardic) people (DNA studies).
From Wiki:
On March 31, 1492, scarcely three months after the reconquest concluded with the fall of the last Nazari Kingdom of Granada, Ferdinand and Isabella promulgated a decree ordering the expulsion of Jews from all their kingdoms. Jewish subjects were given until July 31 of the same year to choose between accepting baptism and leaving the country definitively. Although the decree allowed them to take all their possessions with them, land-holdings, of course, had to be sold, and gold, silver and coined money were forfeit. The reason given to justify this measure was that the proximity of unconverted Jews served as a reminder of their former faith and seduced many conversos into relapsing and returning to the practice of Judaism.
....
The number of the Jews that left Spain is not known, not even with an approximation. Historians of the period give extremely high figures (Juan de Mariana speaks of 800,000 people, and Isaac Abravanel of 300,000). Nevertheless, current estimates significantly reduce this number. (Henry Kamen estimates that, of a population of approximately 80,000 Jews, about one half or 40,000 chose emigration [7]). The Spanish Jews emigrated mainly to Portugal (where they were later expelled in 1497) and to Morocco. Much later, the Sefardim, descendants of Spanish Jews, established flourishing communities in many cities of Europe, North Africa, and, mainly, in the Ottoman Empire.
Never heard of these people. Where in Appalachia do they live, what kind of last names? Now that I think of it, Granny always did make possum soup for colds. The Beverly Hillbenjies.