Mary K. Simkhovitch was born in Newton, Massachusetts, in 1867 to a family of well-to-do Episcopalians. Their house was full of air and light, the rooms were spacious, and the backyard was large. She never dreamed that everyone else in the world didn’t live as she lived, her biographer, Betty Boyd Caroli, tells us in A Slumless America : “People talked about having a house or wanting a ‘nice’ house, but ‘housing,’ especially with a capital H, never came up.” This is something of an irony as she, Mary Kingsbury, would grow up to become the most passionate advocate for public housing the United States would ever know.

The period in American history known as the Gilded Age—the years between the end of the Civil War and the 1890s—was, in the main, characterized by a rapacious industrialization that created wealth and power on an unimaginable scale as well as poverty of medieval proportions.…