In 1915, ...the richest 1 percent possessed about 15 percent of the nation's income....Today, the richest 1 percent account for 24 percent of the nation's income.
I haven't yet fact/back-checked all of the authors figures, but so far this is turning out to be a fascinating piece of journalism. Somewhat depressing, of course, but it contextualizes what we already know about stagnate real wages, income disparities in light of tax breaks for ultra-rich people, etc.
Did federal government policy create the Great Divergence? (1) - By Timothy Noah - Slate Magazine