That has never been true as to Christians or Jews or even Muslims at least not in blue lodge. It was true as to blacks for a time for a certain reason. There are a few requirements to become a mason: You have to believe in a benevolent higher power (Satanists are rejected) and you have to believe in the resurrection of the soul, but further you must be born a free man and able to choose to join of your own free will. In slavery times it was said that a slave could not join because he had a master and therefore could not make his choices freely. And a person born into slavery was not free born. After the end of slavery many still were prohibited for this reason. Even black men who were free born began to be rejected because of the continued tradition and sometimes just plain racism in some lodges. This is how Prince Hall lodges got started and provided many black men with an avenue for petitioning to join. And while most regular lodges dont have a prohibition of any race any longer, some black men still prefer Prince Hall lodges due to the tradition and the human nature to flock to those like yourself.