True for the top 10%. Put in the top 1% (~$500k), though, on the effective tax rate chart at https://qz.com/74271/income-tax-rates-since-1913/ and you'll see it has dropped significantly for that population (by about half) since about 1980.
For a less partisan source, with a neat "pick your income" chart that illustrates the flaws in the Mises argument for sky-high incomes (try anything over ~$500k/year), https://qz.com/74271/income-tax-rates-since-1913/
Despite have marginal rates >70%, very few people ever paid them.