remigration
noun
re·mi·gra·tion (ˌ)rē-mī-ˈgrā-shən 
plural remigrations
: the act of migrating again
especially : the act of returning to one's original or previous home after a migration
One study of pre-1930 immigration showed that Jews and Irish were most likely to stay (a remigration rate of less than one in eight) … 
Mark Jacob and Stephan Benzkofer
Mark Jacob and Stephan Benzkofer 
Word History
First Known Use
1608, in the meaning defined above