There's a two part documentary on the History Channel (part 2 aired tonight) called America:Promised Land.

Caught the end of part 1 and beginning of part 2, very interesting. It's the History channel so, you can expect them take liberties with history and fudge a few things but from what I saw it was good. Saw segments about Chinese immigrant railroad workers and Scandinavian immigrant loggers.
Later in the show..they cover an earthquake in Italy that spurred migration to the US....and the Great Migration of African Americans from the South to the rest of the country.

trailer here



I put the story and vid here because the show is sponsored/underwritten by some DNA testing company because those ads air at every commercial break.