Covers 1789-1930. Offers a web-based collection of selected historical materials from Harvard's libraries, archives, and museums that documents voluntary immigration to the US from the signing of the Constitution to the onset of the Great Depression.
Documents immigration activity on Ellis Island, NY,1880 - 1924. The Ellis Island Hospital was of intense interest and became the subject of a National Science Foundation study in 2007. Functions of Ellis Island were discontinued after 1954.
Grab the continent volume you need and look for your culture. Each entry has a section for History and Cultural Relations and Sociopolitical Organization. These sections can explain why someone chooses to immigrate.