The mental hygiene movement, a dramatic extension of Progressive Era delinquency prevention into America's public schools, began to take form in the United States in 1908, catalyzed by the publication of Clifford Whittingham Beers' "A Mind That Found Itself." That same year, Beers helped found the Connecticut Society for Mental Hygiene, the model for the National Committee for Mental Hygiene (NCMH). The NCMH was founded a year later and would serve as the steering committee for the mental hygiene movement. 1909 also marked Sigmund Freud's only visit to America. Adolf Meyer, a prominent psychiatrist, was in the audience at the Clark University Conference as Freud lectured on psychoanalysis. Meyer was also involved in the founding of the NCMH and would intellectually influence the mental hygiene movement through his theory of psychobiology, which posited that personalities could be known through observing how individuals organized themselves. Mental hygienists accordingly sought to diagnose and treat poorly organized or maladjusted personalities, practices motivated by a progressive faith in the plasticity of personality development. This historiography analyzes this constellation of events, people, and theories that were behind the mental hygiene movement and argues that both hygienists and historians of the movement miss the lessons Freud was trying to teach his American audience. In addition to analyzing the problematic science upon which the mental hygiene movement was built, this analysis argues that historians of the movement continue to participate in the misappropriation of psychoanalysis by conflating its therapeutic and emancipatory projects.