There were certainly more Masons in Great Briton than America, but that did not stop them from being a threat for decades. I don't know about the 19th Century demographics, but I am personally acquainted with Catholic Masons and their church has not been adversarial to Free Masons in my lifetime.

Shaw had family friends who were black and as posted earlier, many Irish immigrants disliked black people. That could be all....or some Irishman may have kicked his butt. Nevertheless, I will search and see if Robert Shaw was a Mason. BTW, the age requirement is 21.