Sanders monumental project People of the Twentieth Century, which he began in the early 1920s, was a series of portraits that aimed to exhaustively document contemporary German society. The project grew to a total of around 600 photographs, classified into seven archetypal categories: The Farmer, The Skilled Tradesman, The Woman, Classes and Professions, The Artists, The City and The Last People. Sanders detached observational style, and his inclusion of images of societys outcasts alongside its success stories, reflected his professed aim to see things as they are and not as they should or could be.
A selection, published in 1929 as Face of our Time, was later seized and destroyed by the Nazis, and Sander was driven to abandon portraiture in favour of landscapes. After the Second World War, he returned to People of the Twentieth Century with renewed vigour.