How the Other Half Lives: Studies among the Tenements of New York (1890) is an early publication of photojournalism by Jacob Riis, documenting squalid living conditions in New York City slums in the 1880s. The photographs served as a basis for future "muckraking" journalism by exposing the slums to New York City's upper and middle classes. They inspired many reforms of working-class housing, both immediately after publication as well as making a lasting impact in today's society. In the 1880s many people in upper- and middle-class society were unaware of the dangerous conditions in the slums among poor immigrants. After the Civil War, the country transformed into an industrial superpower and became largely urban. Also, a wave of unskilled southern European, eastern European, Asian, and Jewish immigrants came to settle in the "promised land" of the United States. This migration was vastly different from the previous booms due to the influx of non-western European and non-Protestant individuals. Therefore, making the split between the "new" and "old" immigrants much larger. In the 1880s, over 5.2 million immigrants came to the United States, with many of these people staying in New York City. This increased New York City's population by 25%, therefore making the tenement problem much more extreme. In the years after the Civil War, many of the former residents of the most notorious slums were wealthy enough to move out of these conditions, or had died in the war. Also, the elevated railway in the Bowery in 1889 transformed this evolving neighborhood back into the squalid, seedy neighborhood it was before the war, and even made it worse. The slums were viewed as a problem by people before the publication of How the Other Half-Lives. Some political reformers believed that a wider distribution of wealth would fix the problem, while the Socialists believed that public ownership and a redistribution of wealth would fix the problem.