Immigration 1820-1920

The Author goes into extra detail while discussing groups between 1820-1920 because "we will see that there are similarities and differences over time both between groups and within groups." This is significant because prior to the 19th century, the differences and similarities that occurred amongst groups were much less evident. For example, groups of immigrants could be made up of mainly males, as immigration evolved and became more common, more women starting immigrating as well. This also was true with Europe demographic emigration. Western Europe had already established a steady flow of emigration before Eastern Europe would begin to emigrate. Now in this new age of immigration (starting at 1880s), not only do groups have similarities and differences with other groups, but also groups are beginning to have similarities and differences amongst themselves because of their vastness.