On June 13, 1877, Joseph Seligman, one of America’s most prominent bankers, showed up at the Grand Union Hotel, in the resort town of Saratoga Springs, New York, and was turned away, because, as the manager supposedly told him, “Israelites” were no longer welcome othere. Seligman (1819-1880), was a German-born banker who owned, with his brothers, banks in New York, London and Frankfurt,...