If you want to go that route now, think of regional and international movement and migration of labor today: hundreds of millions in China alone, to say nothing of Eastern Europe-Central Asia, Latin America to North America, internally in the United States, Western Europe as we all know...And much later - think of Israel after WWII.
However, crucially, by this time the migration of massive and cohesive social units (e.g. "tribes") is over.
With rather few exceptions, whole nations are not v'pokhode gatoviye.
That said, out of interest what are the major exceptions from the past century? That is, general immigration patterns or sporadic refugee movements aren't really counted here.
1. Israel
2. South Vietnam-United States
3. Soviet Jewry-United States/Israel
4. Ethnic cleansing of Prussia
...
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