What type of pictures did Jacob riis take?

Jacob Riis took photographs that documented the harsh realities of life in New York City's tenements during the late 19th century. His images often depicted the living conditions of impoverished immigrants and the urban poor, showcasing overcrowded rooms, bleak environments, and the struggles of daily life. Riis aimed to raise public awareness and advocate for social reform through his powerful, often stark, visual storytelling.