This article documents Henri Bergson's visit to America in 1913. It is based on original research carried out and at the archives of the Sorbonne and universities at which the French philosopher spoke. The conceptual stakes of Bergson's visit turned on the dualisms in his thought. I first highlight the centrality of the problem of dualism in Bergson's early works. I then examine how Americans treated the problem in three contexts: Bergson's close relationship to William James; academic engagements with Bergson's thought, especially that of John Dewey who hosted Bergson; and finally his cultural popularity, primarily in New York City.