I'm not a historian so mods, feel free to remove this comment, but I was interested in whether the numbers were true.

If you look at the numbers of US Federal Individual Income Tax rates (linked) the highest marginal income tax appears to have been in 1944 at 94%. However with regards to the image number, most of the 1950s, the top tax bracket was in fact taxed at a 91-92%. Starting from 1955, the top tax bracket was $400,000 for married filling jointly. Adjusted for inflation, that would make the top tax bracket ~$3.4 million+. Though by 1960, that same amount would be around $3.1 million+. That's a lot of income. I'm not sure how many people in the US would have that amount of money in the 1950s and be subject to those tax rates. However, if we look at the top bracket three years ago, it is $450,000 with the nominal rate being 39.6% which is still lower than the equivalent in 1955 tier of $52,000-$64,000, which paid 62%.

However the second part of the image, I can't really answer: whether the higher tax on the rich was where the money to fund the US' projects during the 50s and 60s came from since I am neither a historian or tax professional. Marginal tax rates aren't usually the best measure of these things. Effective tax rates are a better measure, but I couldn't find much data (if it exists) on effective tax rates during the 1950s beyond estimations that may be biased by political leaning.

Additionally the median income bracket was also taxed at a higher nominal rate in 1955 than today - 22% compared to 15% today. That could be higher or lower depending on the effective rate, since today, the effective tax rate is only 5.3% for the median income bracket.

Mods again please feel free to remove this post if it's against the rules.

Here is my source for the numbers: http://taxfoundation.org/article/us-federal-individual-income-tax-rates-history-1913-2013-nominal-and-inflation-adjusted-brackets [this is a non-partisan organization though it leans conservative]