1890 made low cost mass-reproduction in newspapers, magazines and books possible. The figure most directly associated with the birth of this new form of documentary is the journalist and urban social reformer Jacob Riis. Riis was a New York police-beat reporter who had been converted to urban social reform ideas by his contact with medical and public-health officials, some of whom were amateur photographers. Riis used these acquaintances at first to gather photographs, but eventually took up the camera himself. His books, most notably How the Other Half Lives of 1890 and The Children of the Slums of 1892, used those photographs, but increasingly he also employed visual materials from a wide variety of sources, including police "mug shots" and photojournalistic images. Riis's documentary photography was passionately devoted to changing the inhumane conditions under which the poor lived in the rapidly expanding urban-industrial centers. His work succeeded in embedding photography in urban reform movements, notably the Social Gospel and Progressive movements. His most famous successor was the photographer Lewis Wickes Hine, whose systematic surveys of conditions of child-labor in particular, made for the National Child Labor Commission and published in sociological journals like The Survey, are generally credited with strongly influencing the development of child-labor laws in New York and the United States more generally. In 1900, Englishwoman Alice Seeley Harris traveled to the Congo Free State with her husband, John Hobbis Harris (a missionary). There she photographed Belgian atrocities against local people with an early Kodak Brownie camera. The images were widely distributed through magic lantern screenings and were critical in changing public perceptions of slavery and eventually forcing Leopold II of Belgium to cede control of the territory to the Belgian government, creating the Belgian Congo. In the 1930s, the Great Depression brought a new wave of documentary, both of rural and urban conditions. The Farm Security Administration, a common term for the Historical Division, supervised by Roy Stryker, funded legendary photographic documentarians, including Walker Evans, Dorothea Lange, Russell Lee, John Vachon, and Marion Post Wolcott among others. This generation of documentary photographers is generally credited for codifying the documentary code of accuracy mixed with impassioned advocacy, with the goal of arousing public commitment to social change. During the wartime and postwar eras, documentary photography increasingly became subsumed under the rubric of photojournalism. Swiss-American photographer Robert Frank is generally credited with developing a counterstrain of more personal, evocative,