There is a difference between nominal rate and effective rate. The effective rates are fairly close to the past for high wage earners, lower for low wage earners.

>...In 1958, approximately two million filers (4.4% of all taxpayers) earned the $12,000 or more for married couples needed to face marginal rates as high as 30%. These Americans paid about 35% of all income taxes. And now? In 2010, 3.9 million taxpayers (2.75% of all taxpayers) were subjected to rates that were 33% or higher. These Americans—many of whom would hardly call themselves wealthy—reported an adjusted gross income of $209,000 or higher, and they paid 49.7% of all income taxes.

>In contrast, the share of taxes paid by the bottom two-thirds of taxpayers has fallen dramatically over the same period. In 1958, these Americans accounted for 41.3% of adjusted gross income and paid 29% of all federal taxes. By 2010, their share of adjusted gross income had fallen to 22.5%. But their share of taxes paid fell far more dramatically—to 6.7%. The 77% decline represents the single biggest difference in the way the tax burden is shared in this country since the late 1950s.

http://www.wsj.com/articles/SB100014241278873247051045781516...

I would disagree - prior to WWI there was no income tax. Further, not every state implanted income taxes (some still don't have any)

Some states (Texas) don't have income tax but have very high property taxes to offset this. Or they have high sales tax.

undefined != 0

Seems like in the case of tax, it does. They weren't taking a random % of income in income tax based on what was in the memory cell from the previous call stack. They were taking 0%.