[ATB]

According to that graphic, the previous highest peak of long-term unemployed in the US was in the early 1980s, with around 3m unemployed. The current high peak in 2010, which looks like it may be decreasing now, is just over 6m.

According to the US census, the number of people living in the US at that point was in the low 200ish million, maybe ~230m.

As of right now, in early 2010, it's somewhere around 305-310 million. That number includes a lot of baby boomers (70+ million people, born between 1943 and 1960) who are getting very close to retirement age, especially those whose age and skill set make them unattractive to hire.

Taking into account the nearly 50% increase in US population and the rapid ageing of 70+ million people, many of whom possess skills that aren't necessarily well-suited to the information economy, the chart isn't all that shocking.