Denslow Lewis, a Chicago physician, presented a controversial paper at an 1899 meeting of the American Medical Association (AMA). His work focused on how sex education could improve marital satisfaction, especially for women who suffered physical discomfort during sexual intercourse. The response from his colleagues was less than positive. Most present echoed the sentiments of gynecologist Howard Kelly, who commented, “[The topic’s] discussion is attended with filth and we besmirch ourselves by discussing it in public.” The AMA allowed the paper's inclusion in the annual session but later refused to publish the paper in their journal, noting the controversial nature of Lewis's work.

The twentieth century dawned with even physicians hesitant to discuss sex education. Yet Progressive reformers prided themselves on exposing and solving the nation's problems. Could they do it with what social purity activists believed was the biggest problem of all, sex? According to Delcevare King, a wealthy philanthropist and social purity activist, the best way to improve America was to start a nationwide campaign to change sexual behavior. In 1910, he wrote to New York dermatologist Dr. Prince A. Morrow. Morrow had been working for more than a decade to both bring European venereology work to the United States and to advocate for better sexual hygiene education. Morrow attended international conferences on venereal diseases and was eager to share his knowledge with the American public. King wrote, “That idea of a National Organization as the centre of a National Movement for Sex Education gripped hold of me last night and so I am having to write you this letter.” He suggested the need to end the “conspiracy of silence,” which he called the “most terrible failure of our civilization.” He wanted Morrow to piece together the organization and looked to no less a figure than former president Theodore Roosevelt to be the group's executive. King offered his own money to begin the endowment, saying, “I know something of the difficulties of money raising but I also know what can be done where there is a concrete plan and where earnest men who believe in it, will give most of their time for a brief period toward putting it through.”