In the late nineteenth and early twentieth centuries, most Americans toiled at low-wage factory or agricultural work without health insurance, pensions, or a welfare safety net to rely on during periods of unemployment. The loss of a job or the death of a husband often left families destitute. Since the government took little responsibility for the poor, private charities and limited state-run poverty programs were the only sources of support in times of need.

Confronted with widespread poverty and unemployment during the Great Depression of the 1930s, the federal government instituted the large-scale public assistance programs of the New Deal, greatly reducing the role of private charities in providing for poor families. Widowed mothers could now receive cash assistance under the Aid to Dependent Children program, and the unemployed found work with government-sponsored public works projects. The frightening economic and...