This classic work is out of print and in much demand. The author was one of the first Hispanics in the United States who discovered that many of our ancestors who came from Mexico originally descended from Spanish and Portuguese Jews, many of them settlers from the Monterrey and Saltillo area. They were called conversos , people who converted to Catholicism voluntarily or by force. Some were called Crypto-Jews meaning that they were Catholic by day but practitioners of Jewish rites in secret at night. Santos advances the theory, as other historians have, that the reason many original settlers came north to the Texas border and beyond when this was a wilderness, is that they were fleeing the inquisition to find safety in their ranches. This is a semi-scholarly work, missing annotations, but the product of many years of research.