This book, produced in collaboration with the Yves Klein Archives, tells for the first time the story, through images, of the relationship between Yves Klein (1928-1962), a pivotal artist of the postwar period, and the united States - a relationship based on mutual fascination, reciprocal influence, chance encounters, artists exchanges, and one long journey. Numerous archival documents (photographs, correspondences, etc.), many of which previously unpublished, bear witness to the ties that Yves Klein forged with the United States, depicted through four main periods (Paris, New York, Los Angeles, Paris). We find here the great figures of the American art scene (Leo Castelli, Robert Rauschenberg, Jasper Johns, Marcel Duchamp, Virginia Dwan, Ed Kienholz). This exceptional album opens with an interview of Rotraut Klein-Moquay, who recounts her first trip to the United States with Yves Klein in 1961, and is followed by the presentation of the artist's work as seen through his own eyes as well as those of his contemporaries. It also includes a hitherto unpublished essay by the American art critic Robert Pincus-Witten who personally knew the protagonists of this period. This book is essential in regards to the history of Twentieth-Century Art and features several unabridged archival documents, including the text of the Chelsea Hotel Manifesto.