'Continuation' is inaccurate - your country's historic immigration practices began with "free White persons of good character" [1], and were effectively 'whites only' until 1965 [2]. But the 'nation of immigrants' rhetoric omits this.
Those are the practices they probably benefited from.
Those are the practices they probably benefited from.
[1] https://en.wikipedia.org/wiki/Naturalization_Act_of_1790
[2] https://en.wikipedia.org/wiki/Immigration_and_Nationality_Ac...