This revealing biography of a pioneering photojournalist and social reformer Jacob Riis shows how he brought to light one of the worst social justice issues plaguing New York City in the late 1800s--the tenement housing crisis--using newly invented flash photography. Jacob Riis was familiar with poverty. He did his best to combat it in his hometown of Ribe, Denmark, and he experienced it when he immigrated to the United States in 1870. Jobs for immigrants were hard to get and keep, and Jacob often found himself penniless, sleeping on the streets or in filthy homeless shelters. When he became a journalist, Jacob couldn't stop seeing the poverty in the city around him. He began to photograph overcrowded tenement buildings and their impoverished residents, using newly developed flash powder to illuminate the constantly dark rooms to expose the unacceptable conditions. His photographs inspired the people of New York to take action. Gary Kelley's detailed illustrations perfectly accompany Alexis O'Neill's engaging text in this STEAM title for young readers.