zaltzvasser – You’re talking about America. To be honest, prewar America was always less frum than prewar Europe. I was talking about prewar Europe and the prewar Mizrachi world. I think it’s been established that in prewar Europe and by the Mizrachim/Sephardim, most frum women covered their hair with more than just a sheitel or with something other than a sheitel (eg a snood.) Although we know that in certain countries (not all) in Europe, during certain periods, eg Lithuania in the inter-war era, there was a large problem of certain segments of frum women not covering at all, that was never considered acceptable and the rabbonim in those countries spoke against that phenomenon harshly.
What I was asking earlier was at what point in time, and for what reasons, did a majority of frum women change customs from wearing more than just a wig or something other than a wig, to covering their hair with a wig only.
I read some newspaper articles from the 1800s reporting in Russia that the Russian Czar wanted to modernize Russia, which at the time was highly religious even among the gentiles, and most Russian men sported beards in line with Russian Orthodox Church teachings. So the Russian government banned beards, overtly religious garbs and banned women from covering their hair (something Christian women also did at the time.) These regulations applied to both Christians and Jews, and the Russian police would beat anyone in the street who violated these anti-religious regulations. This was the period Russian peasents started shaving. This was also the same period that many Jews were forced to stop wearing long jackets (kapotes). And this it seems is when Jewish women started wearing wigs-only in large, or even majority, numbers. The reports read were of Russian police arresting and beating Jews (men and women) who violated these regulations by having beards, wearing long jackets or women noticably covering their hair.