This thesis is about the history of American motherhood between 1910 and 1921 when “scientific motherhood” became the winning strategy for solving the nation’s infant mortality crisis. As scientific and medical discoveries in the late-nineteenth century gradually disproved conventional beliefs about the inevitability of infant death, reform-minded Americans grew increasingly intolerant of the nation’s shamefully high rate of infant mortality. Committed to raising public awareness about the extent of infant death in the United States, the infant welfare movement introduced “baby-saving” campaigns like Baby Week and Children’s Year to establish public responsibility for an otherwise private family tragedy. In a time when progressive reformers regularly lobbied the federal government for protections against the dark side of modernization, the infant welfare movement embraced a different sort of progressive solution: it blamed the moms. How did women in the United States become responsible for a national public health problem? With the help of campaign planning manuals, conference exhibits, Children’s Bureau reports, newspapers, and ladies’ magazines, I argue that the infant welfare movement was as much about reforming the modern ideal of American motherhood as it was about saving babies.