Photographer, Art Promoter. In 1884, while living in Germany, he began to learn about photography, writing for photography magazines, winning prizes in photography competitions, and his reputation began to spread as photographic magazines published his work. In late 1892, he bought his first professional level camera, which he used to take two of his best known images, Winter, Fifth Avenue and The Terminal. In the spring of 1893, he became co-editor of The American Amateur Photographer, and wrote technical and his critical content. In 1897 he exhibited in shows in Europe and the U.S. Ten of his prints were selected that year for the first Philadelphia Photographic Salon. In May 1899, he was given a one-man exhibition, consisting of eighty-seven prints, at the Camera Club. In 1901, he was invited by the National Arts Club to put together an exhibition. In 1905, the Little Galleries of the Photo-Secession opened under his management, and had almost fifteen thousand visitors during its first season. In 1916, he saw a portfolio of charcoal drawings by a young artist named Georgia O'Keeffe. By the summer of 1917 he and O'Keeffe had begun a relationship, which would last until the end of his life. He photographed her between 1918 and 1925 in what was the most prolific period in his life, producing more than 350 prints of O'Keeffe. In 1921, he had an exhibition of his photographs at the Anderson Galleries in New York. Of the 146 prints he put on view, forty-six were of O'Keeffe. In 1922, he organized a large show of John Marin's paintings and etchings at the Anderson Galleries, followed by an auction of nearly two hundred paintings by more than forty American artists, including O'Keeffe. In November 1923, he organized a show of O'Keeffe's work, and he spent much of the spring marketing her work. At the end of 1924, he donated 27 photographs to the Boston Museum of Fine Arts. It was the first time a major museum included photographs in its permanent collection. In the same year he was awarded the Royal Photographic Society's Progress Medal for advancing photography and received an Honorary Fellowship of the Society. In 1925, he opened his new gallery, called "The Intimate Gallery", then in 1929, he opened, "An American Place", the largest gallery he had ever managed. In 1936, he exhibited photos by Ansel Adams in New York City, and put on one of the first shows of Eliot Porter's work two years later. The next year the Cleveland Museum of Art held the first major exhibition of his work outside of his own galleries, and he worked himself into exhaustion in preparation. In early 1938, he suffered a heart attack, one of six attacks that would strike him over the next eight years. In the summer of 1946, he suffered a stroke, went into a coma, and died shortly after.