Pedigree analysis has long been an essential tool in human genetics as well as a staple of genetics education. Students of genetics might be surprised to learn that human pedigrees were first popularized in the United States by proponents of eugenics, the pseudoscientific social movement aimed at improving the genetic quality of the human race. Notably, the influential eugenicist Charles B. Davenport employed pedigree charts to support his belief that not only were such medical conditions as Huntington disease and albinism inherited in a simple Mendelian fashion, but so too were such characteristics as alcoholism, criminality, and “feeblemindedness.” We now see the flaws in Davenport's pedigree analysis, but at the time, it was the latest scientific advance. The misuse of pedigree analysis during the eugenics era may serve as a cautionary tale for those who are now harnessing the latest genetic technologies to solve complex problems.