I remember those days. I also remember the idea was to pay off the debt from World War II and the Korean War. It did not work out that way as people making real money, for example, physicians simply stopped working and took long vacations to avoid paying the confiscatory taxes. After all, who wanted to earn 91 cents for Uncle Sam and only 9 cents for himself for every dollar over $200,000.00 he earned.
Ray Stevens has a song about taxes: https://www.youtube.com/watch?v=LVyn6mT5RQ8
Notice Ray made this song after taxes were lowered but again going upwards.
Pope also had personal service contracts and their own corporations where the tax rates were lower. All sorts of way to avoid that rate.