"Multi-racial whiteness"

Given that race isn’t a biologically immutable quality but rather a set of social categories, it seems perfectly reasonable to refer to changing criteria about who belongs in a particular category in terms of “becoming white”.

For instance, Benjamin Franklin, along with many of his contemporaries, famously had a much narrower definition of “whiteness” than is current nowadays:

Here’s a 1916 industrial relations report illustrating the distinction that many employers of the time took for granted between “white men” and “Italians”:

This article discusses similar evolution of racial classifications of various groups of Europeans, illustrated by the contemporary quote in the article’s title, “A Slav can live in dirt that would kill a white man”.

Nobody is claiming that the physical skin color of people of, say, Swedish or Italian or Slavic ethnicity significantly changed between then and now. But it is absolutely true that their perceived qualification to be included in the category of “white people”, according to commonly understood definitions of that category, did change.

We see a similar evolution going on now, for example, in the inclusion of Hispanic/Latinx people in the category “white”. It’s commonly held nowadays that Hispanic and Latinx aren’t racial categories, and may describe people who are either white or nonwhite. But in this 1983 article entitled “Differences among black, Hispanic, and white people in knowledge about long-term care services”, for example, it was taken as a given that “Hispanic” signified a racial category that was neither white nor black.