The Industrial Revolution brought not only new job opportunities but new laborers to the workforce: children. By 1900, at least six percent of all American workers were under the age of 16.

For employers of the era, children were seen as appealing workers since they could be hired for jobs that required little skill for lower wages than an adult would command. Their smaller size also allowed them to do certain jobs adults couldn’t, and they were viewed as easy to manage.

In 1904, the National Child Labor Committee was formed in the hopes of ending the horrors of child labor. Teams of investigators were sent to collect evidence of the harsh conditions children were working in. One of these investigators was the photographer Lewis Hine, who traveled across the country meeting and photographing children working in a variety of industries.

Lewis Hine quit his job as a New York City school teacher to join the National Child Labor Committee. His goal was to open the public’s eyes to the exploitative nature of children’s employment and to help ignite legislative change to end these abusive practices. Although the effects weren’t immediate, the appalling scenes he captured with his camera succeeded in drawing attention to the plight of children in the workforce.

By 1910, the number of children working had grown from 1.5 million in 1890 to 2 million. Congress tried to address the issue in 1916, by passing the Keating-Owns Act that set tighter standards on children’s employment requirements. The law stated that children 14 years or younger could not work in factories, children 16 years or younger could not work in mines, and a work day could not exceed 8 hours, start earlier than 6 a.m. or end later than 7 p.m. Although initially promising, the restrictions would not last long: just a couple of years later, the act was deemed unconstitutional by the Supreme Court.

It wasn’t until the Great Depression that political views on child labor began to change. The work of Hines and the National Child Labor Committee helped usher in reforms such as the National Industrial Recovery Act and the Fair Labor Standards Act of 1938 during the New Deal era. These laws reduced the number of children in the workforce and for the first time set a national minimum wage and maximum hour standards.

Below, take a look at the shocking Lewis Hine photographs that helped America finally take action to crack down on child labor, now a part of the U.S. National Archives collection:

A young shrimp picker named Manuel, 1912.

In Dunbar, Louisiana, Hine met an 8-year-old oyster shucker named Rosy. He discovered she worked steadily from 3 a.m. to 5 p.m., and she told him that the baby of the family will start shucking as soon as she hold the knife. March 1911.

Eight-year-old Jennie Camillo lived near Philadelphia and for the summer worked picking cranberries at Theodore Budd’s Bog in New Jersey, in September 1910.

These boys are all cutters in a canning company. August 1911.

Nine-year-old Minnie Thomas showed off the average size of the sardine knife she works with. She earns $2 a day in the packing room, often working busy late nights. August 1911.

This young worker, Hiram Pulk age 9, also worked in a canning company. He told Hine, “I ain’t very fast only about 5 boxes a day. They pay about 5 cents a box.” August 1911.

Ralph, a young cutter in the canning factory, was photographed with a badly cut finger. Lewis Hine found several children here that had cut fingers, and even the adults said they could not help cutting themselves on the job. Eastport, Maine, August 1911.

Many children worked at mills. These boys here at the Bibb Mill in Macon, Georgia, were so small they had to climb the spinning frame just to mend the broken threads and put back the empty bobbins. January 1909.

Young boys working in the coal mines were often referred to as Breaker Boys. This large group of children worked for the Ewen Breaker in Pittston, Pennsylvania, January 1911.

Hine made a note about this family reading “Everybody works but… A common scene in the tenements. Father sits around.” The family informed him that with all the work they do together, they make $4 a week working until 9 p.m. each night. New York City, December 1911.

These boys were seen at 9 at night, working in an Indiana Glass Works factory, August 1908.

Seven-year-old Tommie Nooman worked late nights in a clothing store on Pennsylvania Avenue in Washington D.C. After 9 p.m., he would demonstrate the ideal necktie form. His father told Hine that he is the youngest demonstrator in America, and has been doing it for years from San Francisco to New York, staying at a place about a month at a time. April 1911.

Katie, age 13, and Angeline, age 11, hand-stitch Irish lace to make cuffs. Their income is about $1 a week while working some nights as late as 8 p.m. New York City, January 1912.

Many newsies stayed out late at night to try and sell their extras. The youngest boy in this group is 9 years old. Washington, D.C. April 1912.