Josie (6 years old), Bertha (6 years old) and Sophie (10 years old) worked regularly at the Maggioni Canning Company.

Work began at 4 AM, and the three would make from $9 to $15 a week. Sophie would do six pots of oyster a day, and her mother, who also worked with her, said, "She don't go to school. Works all the time."

Through such photos, Lewis Hine documented the harsh working conditions borne by thousands of children, who were sent to work soon after they could walk and were paid based on how many buckets of oysters they shucked daily.

Mr Hines wrote of one photograph: ‘All but the very smallest babies work. Begin work at 3:30am and expected to work until 5pm.’

He covered around 50,000 miles a year, photographing children from Chicago to Florida working in coal mines and factories.

These photos helped to raise an outcry against child labor and made the American public widely aware of the scope of the problem.