The progressive era was between the start of the industrial revolution and the start of WWII.
>even white racists don't tend to think white people are all great.
You are so committed to this modern liberal partisan revisionist historiography that you are willing to admit the narrative doesn't make any sense, and yet equally willing to keep at it. That's commitment.
Irish, Italians, russians, and other "inferior" whites were always considered white. "White" has never and will never be the barrier to entry into this country or into the american hierarchy. Looks, charm, stature, sharpness of mind, focus on meaningful pursuits like work, not being too interested in "meaningless pursuits" like art and music. Not being promiscuous, no criminality, no epilepsy, no "feeble-mindedness" or imbecility. This is what race was about. Virginia aristocracy, the Boston Brahmins etc, were spurred on by the leading science and technology of the day, to believe these attributes were genetically inherited and "selected" by nature, which meant they could also be selected with Mendelism. We were not interested in a "white race." Since race was something you could control, we were interested in a "superior american germplasm" a genepool of the best of the best while the rest were sterilized, aborted, deported, or imprisoned in jails, asylums, or reservations. American eugenicists were interested in "building a race." A concept Hitler adopted and was quoted talking about fairly often.
Racism was not white vs black. Its nowhere near that simple