The most prosperous decade of the 20th century was the 1950s.

The top tier tax rate in 1950 was 84%, and that was the lowest it would be until 1964. The rest of the 1950s were at 91%-92%.

The important thing to remember is that nobody ever paid the top-tier tax rate. Instead, they spent their income. When they found themselves $10,000 over the line in 1955, and about to pay $9100 to Uncle Sam, they said "Hold up. Let's spend $10000 on something useful and deduct it as a business expense".

That spending turned into paychecks for the workers who produced the purchased item.

$10,000 over the line in 1988 meant they got to put $7,200 into their stock portfolio, send $2,800 to Uncle Sam, and the worker is laid off because they had no incentive to actually spend their excess income.