"A remarkable study (Norton & Ariely, 2010) reveals that Americans have no idea that the wealth distribution (defined for them in terms of "net worth") is as concentrated as it is. When shown three pie charts representing possible wealth distributions, 90% or more of the 5,522 respondents -- whatever their gender, age, income level, or party affiliation -- thought that the American wealth distribution most resembled one in which the top 20% has about 60% of the wealth. In fact, of course, the top 20% control about 85% of the wealth"
"The ratio of CEO pay to factory worker pay rose from 42:1 in 1960 to as high as 531:1 in 2000"
"Most amazing of all, the top 0.1% -- that's one-tenth of one percent -- had more combined pre-tax income than the poorest 120 million people (Johnston, 2006)."
"Furthermore, if the top 20% have 84% of the wealth (and recall that 10% have 85% to 90% of the stocks, bonds, trust funds, and business equity), that means that the United States is a power pyramid. It's tough for the bottom 80% -- maybe even the bottom 90% -- to get organized and exercise much power."
"only 39 of the 134 countries have worse income inequality."
Who Rules America: Wealth, Income, and Power
It is clear to see how this disparity came about by observing how the top tax rates were slashed:
Top Marginal Tax rates since 1913 & Great Depression (Designing better futures)