Infant formula began in the late 19th and early 20th centuries as a scientific alternative for babies who could not be breastfed. Over the decades, formula recipes evolved in response to nutritional research-but also to major public-health failures. A series of contamination tragedies in the 1970s culminated in the Infant Formula Act of 1980, which established strict nutrient standards, safety rules, and FDA oversight. The current U.S. infant formula system sits at the intersection of public health regulation, nutrition science, industrial production, and market structure—and its complexity became visible during the 2022 nationwide formula shortage.