The father of Dallas businessman Frank Risch may have saved his son’s life before he was even born. Risch’s father was a married executive working in Germany in 1937. He was also Jewish. He came home from work one day to tell his wife he had just been fired. Unlike millions of other European Jews, the elder Risch told his wife they needed to flee as fast as possible. Wisely, he concluded, things would not get better. They would only get worse. “It was very, very difficult,” his son says, “to get out of Germany — and to get into...