Donimeco Cipella works in the card room of the Natick Mills in Natick, R.I. April 1909. (Lewis Hine/Library of Congress)

Frank, a miner boy, on his way home. About 14 years old, Frank has worked in the mine helping his father pick and load for three years. October 1906. (Lewis Hine/Library of Congress)

In 1900s America, child labor was not uncommon. You were likely to find children working not just, say, as newspaper deliverers but also in cotton mills and out in the cotton fields, in mines and even on the docks in Baltimore as oyster shuckers. In 1904, a group of people who abhorred these practices came together and founded the National Child Labor Committee (NCLC) with a mission of “promoting the rights, awareness, dignity, well-being and education of children and youth as they relate to work and working.” They wanted to end child labor. In an effort to ramp up their work against child labor, they decided to hire a schoolteacher and photographer from New York City to document the injustices with a camera. That man was Lewis Hine, and his work would become legendary and secure him a place as a master American photographer.

Two girls working in Calvine Mfg. in Charlotte. January 1909. (Lewis Hine/Library of Congress)

Newsies at Skeeter’s Branch, Jefferson, near Franklin, Mo. May 1910. (Lewis Hine/Library of Congress)

A double exposure showing boys who worked in a mill in Gastonia, N.C. November 1908. (Lewis Hine/Library of Congress)

Hine would spend years travelling the country and documenting children’s working conditions. Often, he had to trick his way into workplaces to take photographs. The NCLC would use his work as part of its publicity and educational efforts. Photo historian Daile Kaplan explained how Hine was able to accomplish the work he set out to do:

“Nattily dressed in a suit, tie and hat, Hine the gentleman actor and mimic assumed a variety of personas — including Bible salesman, postcard salesman and industrial photographer making a record of factory machinery — to gain entrance to the workplace. When unable to deflect his confrontations with management, he simply waited outside the canneries, mines, factories, farms and sweatshops with his 50 pounds of photographic equipment and photographed children as they entered and exited the workplace.”

Hine’s work documenting child labor in the United States helped stir the nation’s conscience and change its labor laws.

Unfortunately, Hine would die in poverty. His photographs, however, have lived on, and he has come to be recognized as one of the most influential American photographers of all time. You can see more than 5,000 of his digitized images at the Library of Congress, here.

Manuel Robello, 10, in Baker Bog, Mass. September 1911. (Lewis Hine/Library of Congress)

Francis Lance, 5, sells regularly on Grand Avenue, St. Louis. May 1910. (Lewis Hine/Library of Congress)

Girls, approximately 10 and 7, who work in a mill in Clinton, S.C. December 1908. (Lewis Hine/Library of Congress)

Boys who work in a mill in Birmingham, Ala. November 1910. (Lewis Hine/Library of Congress)

This girl, who worked in a textile mill in Lincolnton, N.C, said she was 10 years old. November 1908. (Lewis Hine/Library of Congress)

A boy who worked in a mine in Fairmont, W.Va. He said he was 14 years old. October 1908. (Lewis Hine/Library of Congress)

A newsboy in Indianapolis. August 1908. (Lewis Hine/Library of Congress)

Adolescent spinners in the Suffolk Knitting Mills in Suffolk, Va. June 1911. (Lewis Hine/Library of Congress)

Oscar Weston, who worked at Chesapeake Knitting Mills in Berkley, Va. June 1911. (Lewis Hine/Library of Congress)

A composite photograph of a child laborer made from photos of children working in a cotton mill. 1913. (Lewis Hine/Library of Congress)

These boys, approximately 7 and 11 years old, work until midnight every weeknight as pin boys in a bowling alley. Lowell, Mass. October 1911. (Lewis Hine/Library of Congress)

A one-legged boy at a coal mine in Wilkes Barre, Penn. November 1909. (Lewis Hine/Library of Congress)

Edward St. Germain and his sister Delia. She has been working in the Phoenix (R.I.) Mill for eight months; he also works. April 1909. (Lewis Hine/Library of Congress)

Mery Horn, a hunchback. The doctor told her that her case was severe and was being aggravated by the heavy load of papers she carried and that she must stop. She replied, “But I need the spending money. I have to go to shows.” Hartford, Conn. March 1909. (Lewis Hine/Library of Congress)

Nine-year-old Nan de Gallant worked as a cartoner in a canning factory in Eastport, Maine. August 1911. (Lewis Hine/Library of Congress)