Immigration to the United States increased dramatically in the late 19th century, with over 1.5 million immigrants arriving between 1840-1850, nearly half of whom were Irish fleeing the potato famine. By the early 20th century, most new immigrants originated from Southern and Eastern Europe, settling in ethnic enclaves in major cities. However, many native-born Americans grew wary of the cultural changes brought by immigration and blamed newcomers for issues like low wages and overcrowded living conditions. Laws like the Chinese Exclusion Act aimed to stem the flow of immigrants.