Jacob Riis was a photo-journalist in New York in the late 19th century. His photos consist of the photos of tenements which were so crowded surrounded by the slums. These tenements were mainly occupied by the immigrants from the southern and southeastern Europe. Riis made sure that middle-class people know how the other half lives in the society and that there is a gap between the have and the have-nots. This was a danger because people became aware of the conditions of the immigrants and many came in front to challenge the government.