Lewis Hine, who was best known for his use of photography as a means to achieve social reform, was first a teacher of botany and nature studies at the Ethical Culture School in New York. It was while he was teaching that he was given a camera by the head of the school. In his hand, the camera became a powerful means of recording social injustice and labor abuses.

Hine's interest in social welfare and in reform movements led him in 1905 to begin his first documentary series; immigrants on Ellis Island. In 1908 he left teaching to become an investigator and photographer for the National Child Labor Committee (NCLC), and between 1908 and 1916 he traveled extensively photographing child-labor abuses. Hine would manage to gain access to the sweatshops and factories where children were employed, and then, if he could, photograph them at work. Hine inveigled his way into factories by posing as an insurance agent, bible salesman, postcard seller, or industrial photographer. Once inside, Hine quickly would go about his business of photographing the children working. Having been a teacher, Hine was comfortable talking with children and would attempt to get as much information as possible regarding their living conditions, the circumstances under which they were forced to work, and their name and age. If he was unable to determine a child’s age by speaking to him, Hine would surreptitiously measure the child’s height against the buttons on his vest and estimate the child’s age by his height. If Hine was not able to gain admittance to a factory, he would wait outside the gates and photograph the children as the came to work. He visited children and families who worked at home and he wrote with impassioned sarcasm of the "opportunities for the child and family to enlist in the service of Industry."

Hine's photographs were used to make lantern slides for lectures and to illustrate pamphlets, magazine articles, and exhibitions. Through his photographs, Hine was able to inspire social change. His photos documenting the horrid conditions under which children were employed, made real the plight of these children. This led to the passage of child labor laws. Not only did Hine document the horrors of work, he also depicted the dignity of labor. This is best seen in his photos of the construction of the Empire State Building. From 1930 to 1931 he took hundreds of pictures of the Empire State Building under construction. These photos, as well as photographs of factory workers and other laborers, were published in Men at Work. While Hine's early photographs were often published, by the 1930s, interest in his work had declined. In 1938 he was denied a grant to photograph American crafts people at work. The Photo League in New York publicized his work, but it was not until a number of years after his death that he again received wide recognition. A new monograph was recently printed entitled, Lewis W. Hine Children At Work by Vicki Goldberg.