Lewis Hine is most famous for his photographs of the construction workers who helped build the Empire State Building in 1930.
But in the years before he celebrated the heroic labour of these men working high above Manhattan, Hine used his photographs to campaign for social reform.
In 1908 the then-sociology professor was hired by the National Child Labor Committee to document how children as young as seven were working in cotton mills and coal mines.
Over a decade he took thousands of photographs that helped convince US lawmakers to introduce new industrial regulations to protect children.
Alison Nordstrom, senior curator of photographs of the George Eastman House in Rochester, New York, talked to the BBC about the new book of this historic photographer's work, entitled simply Lewis Hine.
Photographs courtesy of George Eastman House International Museum of Photography and Film, in Rochester, NY.
George Eastman House holds the Lewis Hine archive.
Produced for the BBC by Tracy Sutherland - April 12th, 2012.