The following paper assesses the impact of the five lectures given by Sigmund Freud during his brief stay in America in 1909. I will argue that the talks he presented mark a distinct shift in American self-understanding: American approaches to mental illness had been based on the so-called somatic style, which held a purely mechanistic view of the human mind and body, thus treating only the symptoms of apparent psychological ailments. Acknowledging the psyche as a factor in its own right, psychoanalysis greatly challenged American ideas, and Freud’s theories about infantile sexuality undermined the contemporary American emphasis on Civilized Morality. After his departure, a heated controversy ensued among professionals in the US. However, in the wake of Freud’s lectures, American psychiatrist James J. Putnam turned his back on the somatic style he had previously practiced. In the winter of 1909-10, Putnam set out to defend the concept of psychoanalysis among his American colleagues and thus prepared the ground for its acceptance into the mainstream of US psychology. Simultaneously, Freud’s theories underwent a significant Americanization and, in turn, freed American society from the constraints of a Puritan morality and gave the nation a new sense of self-awareness.