In the early-20th century, the Rockefeller Foundation's International Health Board (IHB) traveled to several areas around the world to tackle rural sanitation and hookworm disease. Yet, few historians have endeavored to evaluate the consequences of IHB-led interventions for local populations. This report describes research conducted at the Rockefeller Archive Center in order to evaluate the effectiveness of hookworm-eradication measures in Brazil (for my first book project) and worldwide (for a second major research project). I discuss the general content of the hookworm-eradication reports and offer insights into how this body of evidence could be used for scholars working outside of health- or medicine-related fields of inquiry. I argue that the content of the hookworm control reports could be better used by historians with a general interest in inequality.