Jacob August Riis (May 3, 1849 - March 26, 1914), a Danish-American muckraker journalist and slum and school reformer, was born in Ribe, Denmark.
He came to America in 1870 and wrote for the New York Evening Sun newspaper. As a pioneer investigative journalist, he went undercover working at a meat packing factory. His book How the Other Half Lives (ISBN 0140436790), pioneering photojournalism, and friendship with Theodore Roosevelt (then New York Police Board of Commissioners head) led to positive changes for New York tenement dwellers. Jacob Riis National Park in the borough of Queens, New York is named for him.