We provide a historical perspective toward the current public school practices of American sex education. The primary time frames include the progressive era (1880-1920), intermediate era (1920-1960), the sexual revolution era (1960s and 1970s), and the modern sex education era (1980s to the present). In each period, we highlight key developments that affect educators' current decision making as public sex education continues to develop and morph in the context of contemporary society. We show that an apt understanding of sex education's past is critical for making prudent decisions about its future.