Between the 1880s and 1900s, millions of new immigrants arrived in the United States from southern and eastern Europe, fleeing poverty, persecution, and seeking opportunities. They faced difficult journeys and were processed through immigration centers like Ellis Island upon arrival. The new immigrants largely settled in cities and took on unskilled jobs, living in overcrowded tenement housing. As cities grew rapidly, urban infrastructure expanded through skyscrapers, subways, and parks to accommodate the large populations. However, this also led to problems like unsanitary living conditions that reformers worked to improve through legislation, investigative journalism, and social programs.