J. Presper Eckert (the man in the foreground turning a knob) served and John Mauchly (center) designed ENIAC to calculate the trajectory of artillery shells. The machine didn't debut until February 1946, after the end of World War II, but it did launch the computer revolution.
Source of articles:
http://www.zdnet.com/photos/images-birth-of-the-first-computer/11161#photo
Note: other pics on this complete read of the first computer.