Toward the end of the century, some photographers focused their cameras on ordinary people. In New York, newspaperman Jacob Riis wrote about the plight of the poor. When he learnt of
flash photography, he used it to expose the dark, squalid living conditions of immigrants and children in the city. These were later collected in a book of street photography called How the Other Half Lives. His photos helped bring about new child labour laws and better schools, proving social documentary photography could effect social change. A few decades later, sociologist Lewis Hine used his camera to expose the cruelty of child labour in the Appalachian Mountains.