The racialization (or whitening) of Irish-Americans, Italian-Americans, and European Jewish Americans largely transpired after this historical event:

Race has additionally been a factor in migration itself. In an assortment of ways explicit to various groups, until well into the 20th century, American law has confined the passage of Africans, Asians, and other non-European people groups into the US.

Explanation:

The ascent of ethnic groups out of progressive floods of movement in the nineteenth and twentieth century has not been the just or even the significant well spring of social separation and on occasion fracture in American history.

A considerably more established source is race, which has been a generally huge and standing power in the organizing of society, governmental issues, and financial aspects and in the shaping of American self-comprehension since the beginnings of European settlement in North America. In sharp difference to the deliberate movement that carried a great many Europeans to these shores, Africans, Native Americans, and Mexicans were fused into the populace forcibly, through enslavement and conquest.