New immigrants to New York City in the late 1800s faced grim, cramped living conditions in tenement housing that once dominated the Lower East Side. During the 19th century, immigration steadily increased, causing New York City's population to double every decade from 1800 to 1880. To accommodate the city's rapid growth, every inch of the city's poor areas was used to provide quick and cheap housing options.

Houses that were once for single families were divided to pack in as many people as possible. Walls were erected to create extra rooms, floors were added, and housing spread into backyard areas. To keep up with the population increase, construction was done hastily and corners were cut. Tenement buildings were constructed with cheap materials, had little or no indoor plumbing and lacked proper ventilation. These cramped and often unsafe quarters left many vulnerable to rapidly spreading illnesses and disasters like fires.

By 1900, more than 80,000 tenements had been built and housed 2.3 million people, two-thirds of the total city population.

Jacob Riis, who immigrated to the United States in 1870, worked as a police reporter who focused largely on uncovering the conditions of these tenement slums. However, his leadership and legacy in social reform truly began when he started to use photography to reveal the dire conditions in the most densely populated city in America. His work appeared in books, newspapers and magazines and shed light on the atrocities of the city, leaving little to be ignored.

In 1890, Riis compiled his work into his own book titled, How the Other Half Lives. As he wrote, "every man’s experience ought to be worth something to the community from which he drew it, no matter what that experience may be.” The eye-opening images in the book caught the attention of then-Police Commissioner, Theodore Roosevelt. Riis' work would inspire Roosevelt and others to work to improve living conditions of poor immigrant neighborhoods.