From Remapping Debate--
At a time when both the President and his GOP adversaries are looking to lower income tax rates, it is helpful to get some historical perspective — a process that quickly reveals that federal income tax burdens are near post- World War II lows.
Users of this  tool will be able to make a host of observations. Two that Remapping Debate have noted: the halving of the tax burden from 1945 to 2011 for a married couple with taxable income (in 2010 dollars) of $1,000,000 saves that couple more than $340,000 over the tax bill that they would have had to pay back in 1945. A similar percentage reduction in tax burden for a married couple with taxable income (in 2010 dollars) of $30,000 saves that working class couple only about $3,350 over the 1945 bill.
Check out this great, interactive resource here !