Alfred Stieglitz was born in New York but it is in Berlin, where his family settled in 1882 that he discovers photography. He promptly takes part to the pictorialist movement, a follower of a naturalistic aesthetic. When he returns to New York in 1890, he is a celebrated actor of the photographic activity of the city, founding the Camera Club and Photo-Secession alongside Clarence White, Gertrude Kasebier and Edward Steichen. Alfred Stieglitz depicts soft toned and textured urban views with a strong highlight of atmospheric moods. From the mid 1910s, the American photographer begins to think photography differently preferring neat ‘straight photography’ to its manipulation to make it ressemble drawing or painting. Influenced by Cubism but also Paul Strand’s images and his partner, Georgia O’Keeffe’s paintings, he explores his everyday surroundings with a sharp and contrasting aesthetic. Making portraits of his lover becomes one of his main occupations between 1917 and 1925, depicting a composite work that investigates the fragmentation of the self, the rapid pace and evolution of the modern society, the multiple facets of one’s personality and, finally, the idea that a photograph reflects the feelings of the photographer for his subject. Not only has Alfred Stieglitz been recognized as the influential advocate of modern photography but also has he been a vital force in the development of modern art in his country, introducing European modern artists such as Paul Cézanne and Francis Picabia to the public and nurturing America’s own modernist figures via his art galleries and publications.