This monograph delves into the influential career of Alfred Stieglitz, a pivotal figure in American photography who played a crucial role in its recognition as a legitimate art form. It explores how Stieglitz bridged Pictorialist photography's aesthetic focus in the late 19th and early 20th centuries, with the emergence of 'straight' photography in the 1920s and 1930s. The book provides a comprehensive overview of his contributions to the American modernist movement, highlighting his impact on the evolution of photographic art and his enduring legacy in shaping artistic expression in photography.