In September 2010, Slate Magazine published "The United States of Inequality," a 10-part article written by Timothy Noah.
The article is still available in Slate's archives, but an infographic slideshow that accompanied the article is not. Thankfully, The Wayback Machine has a copy, and one of the slides in particular resonates just as strongly today:
A second slide illustrates one of the reasons this second Gilded Age has come to be:
Update: This chart from the Economic Policy Institute illustrates what's happened: