In March 2015 the fifth White House science fair opened with the title “Diversity and Inclusion in STEM [science, technology, engineering, and math].” Addressing young attendees and parents, President Barack Obama declared, “We get the most out of all our nation’s talent . . . reaching out to boys and girls . . . of all races and all backgrounds. Science is for all of us. And we want our classrooms and labs and workplaces and media to reflect that.”1 By 2015 statements such as the president’s sounded unremarkable. Other national leaders, educators, scientists, and engineers repeatedly declared that they wanted to welcome all youngsters into STEM, regardless of gender, race, ethnicity, or other identity markers. But in the mid-twentieth century, no such campaigns to promote STEM diversity existed. The idea of science and engineering “for all of us” would have struck many midcentury Americans as strange. In that era, educational institutions, professional organizations, and popular culture encouraged white boys to grow up to become scientists and engineers while steering other children away. Young women were blocked from much of the scientific and engineering world; the relatively few who persisted often faced daunting opposition.2