In 1907, he became a photographer for the National Child Labor Committee. The NCLC gave Hine his first assigned project, to photograph a New York tenement. Later that year while still at Columbia University graduate school Hine was assigned The Pittsburgh Survey, An ambitious project which aimed to give a detailed view of an industrial city. The survey would describe the gap between the largely unskilled immigrant workers and the affluent managers and executives. The aim of the survey was to highlight and hopefully create an understanding of the social and economic inequalities that were present.
Between 1906 and 1908, Hine worked as a freelance photographer for The Survey, a leading social reform magazine.
In 1908, the NCLC assigned Hine to photograph child labor practices. Hine continued this work until 1917. During this period he travelled widely across America photographing children at work in textile mills, factories, canneries, mines and farming.
Bowling Alleys, connected with Geo. P. Grays, "Bastable Caf " on Genesee St. About 8 very small boys employed here. Work until midnight. Photo taken at 11:30 P.M. Location: Syracuse, New York (State)
1909 Boy Woodpickers Under Way. Location: Boston, Massachusetts
1908 October Bill, a carrying-in boy, Canton Glass Works, Marion, Indiana. Gets $.80 a day or night.
In 1917 Hine accepted a position with the American Red Cross were he documented their relief work with refugees and displaced peoples in post war Europe.
In 1920 he returned to New York and was assigned to the American Red Cross National Headquarters. Here he photographed the drought relief work in the American South, for the Tennessee Valley Authority and made photographic studies of life in the mountains of eastern Tennessee.
He also served as chief photographer for the works progress Administration's National Research Project, which was set up to study changes in industry and how this effected employment.
In 1930 Hine was hired to photograph the construction of the Empire State Building. Hine photographed the workers in many precarious positions while they secured the framework of the structure. In order to obtain the best vantage points, Hine was swung out from the building in a specially designed basket.
The series of photographs he produced lead to the 1932 book Men at Work. Critics noted that he had managed to show the human contribution to modern industry while depicting the dignity and power of the American worker. At this time he even exhibited at the 1933 Worlds Fair.
By 1936, Hine was appointed head photographer for the National Research Project of the Works Progress Administration until his death in 1940 after complications from surgery.
The Library of Congress holds more than 5,000 Hine photographs 5,100 photographic prints and 355 glass negatives, given to the Library of Congress, along with the NCLC records, in 1954. NCLC records in the Library of Congress Manuscript Division contain approximately 65 reports, about 30 of which were authored by Hine.