The right wing does not consider the 1950's to be a golden age of anything, the 1950's were a decade of tepid growth after the war. The country was ripe with economic opportunities simply because the war drew to a close. As you might imagine, the casualties of said war greatly reduced the supply of able bodied workers, but the demand was high. This relation stimulated wages upwards, hence the relative prosperity of citizens. The top marginal tax rate was 91%, however tax avoidance was high, exemptions were plentiful and the actual effective top marginal tax rate was 42%. With those factors accounted for, tax revenues were relatively the same and the top 1% paid in just as much as they have prior, in many cases less than before the war.
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https://taxfoundation.org/taxes-rich-1950-not-high/
If we're taking about prosperous times, we should talk about the roaring 20's instead. The only problem with that decade was caused by market speculation which eventually led to a crash, which is not unusual on a market that's speculative by nature.
As far as prosperity goes, people are the most prosperous when they are taxed the least and when the demand for their labour is high. The relationship between tax revenues and tax rates is not linear - taxing people at higher rates does not mean that revenues will be higher. For instance, if you told me that I am allowed to earn X and anything I earn past the point of X will be automatically seized by the state, I am simply not going to work past that point because I don't fancy being a slave. What you've effectively done is you kept revenue stagnant, but you killed my productivity and therefore stifled the economy. I'm taxed the same amount, but there is less wealth being generated over time. There is a golden mean somewhere between 0% and 100%, and it's not immediately obvious where that golden mean is, it's subject to fierce debate.