“Long ago it was said that “one half of the world does not know how the other half lives.” That was true then. It did not know because it did not care. The half that was on top cared little for the struggles, and less for the fate of those who were underneath, so long as it was able to hold them there and keep its own seat. There came a time when the discomfort and consequent upheavals so violent, that it was no longer an easy thing to do, and then the upper half fell to inquiring what was the matter. Information on the subject has been accumulating rapidly since, and the whole world has had its hands full answering for its old ignorance.”
Jacob A. Riis, How the Other Half Lives