Poor, population, underpaid, migration
Why did more than 50 million people leave Europe for the United States in the second part of the 19th century? To understand the largest migration in history you have to look to the hopelessly poor living conditions which many people in the Old World lived under. To people living in an overpopulated and underpaid. Europe the idea of going to America where nothing was impossible but where "everything" was possible was immensely attractive.
Strandberg, Hans J.
"Julius Strandberg and "The Almost White Child","
The Bridge: Vol. 20
, Article 8.
Available at: https://scholarsarchive.byu.edu/thebridge/vol20/iss1/8