When the corporate income tax was enacted in 1909, the "income" levels were pretty high. Also, when the personal income tax was enacted as part of the tariff of 1913, the income levels were high enough that it didn't affect most people. Plus it wasn't supposed to attach to what you earned through the sweat of your brow. It only really started to affect working people during WWII and the "Victory Tax" that started withholding. It's been downhill since then.