I was reminded by Dan Brown during a recent meeting how rich in data Minard's map of Napoleon's march to Moscow is (published in 1861). I once attended a Tufte seminar where he stated that this might be the best statistical graphic ever drawn. You be the judge (click on the map).

The tan line shows Napoleon's troops traveling from Paris to Moscow, the black line shows their return to Paris. The width of the lines represents the size of the troops. You will also see the actual number of troops along the way, location/direction of troops and temperature on elapsed days.

By the way, for those of you who have read Tufte's other work, he published a new book earlier this year entitled Beautiful Evidence.