«Once the visitor was told rather repetitively that this city was the melting pot; never before in history had so many people of such varied languages, customs, colors and culinary habits lived so amicably together. Although New York remains peaceful by most standards, this self-congratulation is now less often heard, since it was discovered some years ago that racial harmony depended unduly on the willingness of the blacks (and latterly the Puerto Ricans) to do for the other races the meanest jobs at the lowest wages and then to return to live by themselves in the worst slums.»