"Nations Are Built of Babies" documents a national campaign by Ontario physicians to reduce infant and maternal mortality in the early twentieth century. Armed with a secure faith in science and aided by the increasingly important position of experts in Canadian society, the medical profession tackled the "national tragedy" of infant and maternal mortality by advocating "scientific motherhood." Canadian mothers were believed to be handicapped by an ignorance that could be remedied only through expert tutoring and supervision of child-rearing duties. Working within a Marxist-feminist framework, Cynthia Comacchio demonstrates that the campaign was part of a conscious plan to modernize Canadian families to meet the ideological imperatives of industrial capitalism. Doctors reasoned that if infants could be saved and their physical, mental, and moral health regulated, the benefits in socio-economic terms would more than offset any individual or state investment.