(CP-1)

Located at the University of Chicago, underneath an abandoned football stadium (Stagg Field), Chicago Pile Number One or CP-1 went critical on December 2, 1942.

Constructed in an abandoned squash court it was here that mankind first harnessed the power of the atom. Although it only produced 0.5 watts of power it was all that was needed to enter the next phase of the United States' development of The Bomb.

The pile contained 771,000 pounds of graphite, 80,590 pounds of uranium oxide and 12,400 pounds of uranium metal when it went "critical." It cost about $1 million to produce and build. The pile took the form of a flattened ellipsoid which measured 25 feet wide and 20 feet high.