How did the Eugenics Record Office collect and use family information in the United States?

The Eugenics Record Office (ERO), established in 1910 at Cold Spring Harbor, New York, functioned as a national repository and clearinghouse for eugenics data in the United States. To collect information, the ERO trained fieldworkers to gather data on human traits and diseases throughout the country.1

The office used this information to compile an index of traits within American families, which served several discriminatory purposes:1

• Research and Analysis: The ERO supported investigations into inheritance patterns of specific human traits and diseases, which were often used to categorize individuals as "feebleminded," "criminalistic," or otherwise "socially inferior".1
• Policy Influence: Harry H. Laughlin, who superintended ERO activities, used these family tabulations to provide testimony to Congress. This data was instrumental in the passage of the Immigration Act of 1924, which restricted immigration based on the perceived "genetic inferiority" of certain ethnic groups.1
• Reproductive Control: The ERO advised on the "eugenic fitness" of marriages and promoted model laws for the involuntary sterilization of institutionalized populations, leading to the systemic violation of human rights across many U.S. states.1