I didn't demand unbiased references, I asked you to share one if you had it. That last article's references have potential :)
"White people" was a recognised expression earlier than I'd been led to believe, thank you.
But as to when it became a dominant self-definition ("I am White like other White people" supplanting e.g. "I am Calvinist" or "I am a man of Kilkenny") I defer to Ignatiev's rather extravagantly well-researched hate tract. (I mean, book.)
The level of special-pleading and reaching for any excuse to dismiss the suffering of "White" slaves in that The Conversation article is chilling, and the author seems personally obsessed with "reparations for slavery", and wants to reserve them for one politically-useful clique.
That author hates as well or better than Ignatiev, but is only 10% the scholar. IIRC Ignatiev is quite willing to admit death rates were higher for slaves under "indentured servitude" compared with those under African chattel-slavery laws. He minimises, but he doesn't lie.
Srsly, you might like the work, whatever you think of the man.