This document discusses mass transatlantic migration between 1870-1914, when over 23 million immigrants arrived in the United States, most through Ellis Island. During this period, immigrants also ventured to other new world countries like Canada and Argentina seeking work. While intra-European migration was often a means to eventually leave for the new world, the scale and diversity of immigration to the US was much greater than in other countries. Native-born Americans increasingly resented immigrants and accused them of social and economic problems.