For 10 points, who was this Danish immigrant and activist who gained national fame in 1890 with his photo-journalistic book How the Other Half Lives?
A police reporter for the New York Tribune from 1877, he became known for his vivid descriptions of crime in the Mulberry Bend and Five Points areas.  The unspeakable poverty and overcrowding that he witnessed there led him to become an activist, promoting tenement regulation, care for homeless children, the construction of playgrounds, and the closing of police lodging houses, which police commissioner Theodore Roosevelt finally did at his urging.  He began illustrating his articles with his own photography of the squalor, and his subsequent article, "Flashes from the Slums" in 1888 was highly successful. For 10 points, who was this Danish immigrant and activist who gained national fame in 1890 with his photo-journalistic book How the Other Half Lives?
A police reporter for the New York Tribune from 1877, he became known for his vivid descriptions of crime in the Mulberry Bend and Five Points areas.  
Jacob Riis