A comparison of percent job losses during the current recession with past recessions indicates that the US is experiencing the deepest drop in national employment since World War II. In other words, most Americans alive today have not experienced a deeper decline in national employment during their lifetimes.
The chart below tells the story (click to expand).
Note that the red dotted line depicts the percent job losses through May, less the 411,000 temporary census jobs the government recently added (and which will end in July).
Source: McBride, B (2010, June 4), May Employment Report: 20K Job ex-Census, 9.7% Unemployment Rate, Calculated Risk.