One of the first advocates for the art of photography was Peter Henry Emerson (1856 - 1936). Emerson bought his first camera in 1881/1882 and published his first book of photos in 1886 titled Life and Landscape on the Norfolk Broads.
He left his career as a surgeon that same year to devote his time to photography and writing. He published several more books on photography and helped form the Camera Club of London. His efforts helped photography gain world-wide acceptance as art.
Emerson believed in Naturalistic Photography. He thought the final print should be made from one shot and not manipulated during printing. These beliefs went against the common practice of taking multiple shots of differing shutter speeds and combining as many as twenty in the making of one print.

Peter Henry Emerson - The Old Order and the New - 1886
Alfred Stieglitz (1864 - 1946) was an excellent photographer and promoted the art of photography through his publication Camera Work. The publication featured the images of some of the finest photographers of the day, discussed photography and art, and reviewed exhibitions including those of Stieglitz's own Gallery 291. The quality of the 559 images printed in Camera Work from 1903 through 1917 was unsurpassed.
After Camera Work ceased publication Stieglitz continued to promote photography though his art galleries which featured work by Paul Strand, Elliot Porter and an up and coming photographer by the name of Ansel Adams.

Alfred Stieglitz - Winter, Fifth Ave - 1892
Ansel Adams (1902 - 1984) took the art of photography to a new level. His images of Yosemite and the Sierra Mountains came alive on paper and his prints are still popular today - www.AnselAdams.com
Adams dreamed of being a concert pianist and began studying seriously when he was thirteen.
When he was fourteen he talked his family into vacationing in Yosemite. After they arrived his parents gave him his first camera, a Kodak Box Brownie.
He continued to study and work in both music and photography but in 1930 decided that the camera and not the piano would be his destiny. His mother pleaded with him not to give up the piano because the "camera cannot express the human soul." Adams responded "Perhaps the camera cannot, but the photographer can!"
Adams believed "The negative is the equivalent of the composer's score, and the print the performance". When he made prints from his negatives he would dodge and burn (lighten and darken) select areas of the scene until the final print came as close as possible to what he visualized when he pressed the shutter.
Adams thought Stieglitz had the best explanation of the process of creating photographic art. Stieglitz said "I have the desire to photograph. I go out with my camera. I come across something that excites me emotionally, spiritually, aesthetically. I see the photograph in my mind's eye and I compose and expose the negative. I give you the print as the equivalent of what I saw and felt."
Today's photographers have access to tools even these visionaries could never have imagined. However the elements of a successful fine art photograph are still the same - vision, composition, execution and printing.

Ansel Adams - Clearing Winter Storm - 1935