Marxist categories presumed a white American working class.

Evidence

Unfortunately, throughout the nineteenth century and into the next, much of the theoretical grammar brought by Marx, Engels, Lenin, and other Marxists to the analysis of American phenomena and processes was similarly naive. It was naive because of its ahistoricity and its tendency toward the use of aggregative concepts to the point of superfluousness. Ultimately, its naivete was contradictory: at the historical point of massive immigration, the application of race and class, the grammar’s two most fundamental categories, presumed the existence among the majority of American workers of a white working class; thus the eventual appearance of a Black nation suggested an opposite historical momentum. — Cedric J. Robinson, Black Marxism_ The Making of the Black…, 1064

Categorization

• DEEPTHINKING: The contradiction that Marxist class analysis presupposed whiteness at the moment of massive immigration — a dense point connecting race, class, and nation that resists simple summary.
• XREF: Echoes W.E.B. Du Bois’s arguments in Black Reconstruction about the psychological wages of whiteness, a natural cross-source connection.