C Columbus was indeed a Jew - and it was not a secret.
Spain kicked out all Jews and they went seeking a new home for themselves.
BTW, the religious warfare endemic in Europe is why those from Protestant countries, particularly the Anglo-Saxon peoples, tend to denigrate Spanish culture and all things Hispanic. That's also true in the other direction, of course. But since we live in the English-Speaking World, (for a while longer anyway) we never get the whole picture.
Stop and think that the original 13 colonies and the first United States were tiny indeed compared with the Spanish possessions in the New World, and that major Spanish cities in the New World were already over 100 years old when the Pilgrims arrived.
The Spanish-speaking Jews kept speaking Spanish where they moved to--many of them to the Ottoman Empire.
I once heard someone tell about a Turkish consul stationed in Chicago whose wife did not speak English. She had no trouble there because she was of Sephardic Jewish background and could go to the Hispanic neighborhoods in Chicago and get along fine in the stores using her Spanish.