In the first half of the 20th century, the theory of eugenics grew in popularity. Eugenics was first developed by scientist Francis Galton, who argues that scientists should supervise reproduction in society to encourage the birth of healthy, fit children. Eugenics has two branches: positive eugenics, which aims to encourage reproduction to pass down beneficial genetic traits, and negative eugenics, which seeks to forbid individuals who hold supposedly detrimental genetic profiles from reproducing and passing on their genes. Some eugenicists, such as Dr. Harry J. Haiselden, took negative eugenics to the extreme, killing infants with disabilities. In many cases, eugenicists were openly racist and classist, believing that Black and poor people had inherently “inferior” genes.

The eugenicist Margaret Sanger became especially interested in limiting the population growth rates of Black people—particularly in Harlem, a predominantly Black neighborhood in New York City. Sanger put together a journal named “The Negro Number” that featured contributions from prominent Black thinkers such as W. E. B. DuBois. The articles in the journal argued that the Black people who reproduced the most were those who were “least intelligent and fit, and least able to rear their children properly” (197).