There has never been a "white culture" in an enduring and stable way. Something resembling a multi-ethnic white monoculture developed during the 1950s, resulting from the social mixing of whites in WW2 service. But that's very new and not very robust -- certainly lacking deep roots.
There have been a lot of very distinct cultures held by white people -- German, Irish, Finnish, etc -- but they were all quite different.
"Our new government is founded upon exactly the opposite idea; its foundations are laid, its corner- stone rests, upon the great truth that the negro is not equal to the white man; that slavery subordination to the superior race is his natural and normal condition. This, our new government, is the first, in the history of the world, based upon this great physical, philosophical, and moral truth."
It seems that even a century earlier than your 1950's monoculture, the white people of America were not just calling themselves white, but in fact, were creating political philosophy centered around their white identity.
Not their polish, German, Irish, Finnish identity.
What's my opinion on the speech? That it's true that people conceptualized of a "white race" prior to the 1950s, but it doesn't contradict my claim that an inclusive white identity lacks long historical precedent, historical pre-eminence or robustness. If it were robust and pre-eminent, the KKK wouldn't have targeted white Catholics or Jews. If it were robust and pre-eminent, Irish Americans wouldn't have been treated poorly in much of the US. If it were robust and pre-eminent, "race scientists" of the late 19th and early 20th century would not have divided whites into distinct sub-races with purportedly unique characteristics. Ethnic balkanization among whites in the US persisted throughout the first half of the 20th century – think of the distinct ethnic mobs and tensions that characterized NYC – and mass conscription during WW2 substantially changed this.
If it were robust and pre-eminent, white people wouldn't have seceded from the country to create a white country, a literal ethno-state.
Oh wait!
Is what it is, you clearly already have your conclusion.
P.S. northern chinese make fun of southern chinese (cantonese), does that preclude their ethnicity and culture? I fail to see how targeting Irish means anything. Chinese target their own sub-ethnicities all day long. As does every other ethnic group.
He's being pretty clear, and your response is a little obtuse.
He's not saying that nobody called themselves "white" before 1950.
He's saying that the demographics of "whiteness" in the mid-1800s are different than the demographics of "whiteness" now, and so the term is arbitrary.
There have been a lot of very distinct cultures held by white people -- German, Irish, Finnish, etc -- but they were all quite different.