George Washington and many of the Founding Fathers questioned European mass migration in their letters, diaries, and other documented sources. The Founders feared heterogenous society will erode the unity of the newly formed United States. The American Republic and their Identity are linked with the
English, Ulster-Scots, Scots, and Ulster-Irish, as the Founders opposed mass migration that would demographically replace the Anglo-Saxon people in the United States.
Source:
George Washington to John Adams, 15 November 1794