On June 5th, 1870 Jacob Riis arrived in New York with 40$ and a revolver. Riis was one of the millions of immigrants arriving on the shores of the United States at the end of the 19th century. Seeking a better life, the immigrants were packed into the tenements and slums of New York. In the 1880s, the Lower East Side was the most densely populated place in the world. Riis's documentation of the inhabitants of these neighborhoods would make him famous and drive a reformist movement.