Elaborate please because I’m getting mixed vibes from this comment and Wikipedia’s interpretation of the event referenced.

I highly doubt racism was invented.

Racism was invented long before that, as a proxy of the invention of race (specifically "white" as a racial category) to justify chattel slavery under the pretense of white supremacy.

So you're correct, for certain definitions of "working class," but I find attempts to dismiss anti-racism (and increasingly LGBT ) progressive efforts as being merely a distraction from class struggle to be tone-deaf at best, and counterproductive at worst.

Intersectionality is a thing. Race shapes class - especially in the United States where class was literally built around racial caste and identity - and class shapes race. We can have praxis along more than one dimension.