The first graph is from Doug Short of dshort.com (financial planner): "Four Bad Bears".
Note that the Great Depression crash is based on the DOW; the three others are for the S&P 500.
The second graph shows the S&P 500 since 1990.
The dashed line is the closing price today.
This puts the 15% rally into perspective - the S&P is still off more than 50% from the 2007 high.