Caption:
The reactor was a pile of uranium and graphite blocks, assembled under the supervision of the renowned physicist Enrico Fermi, in collaboration with Leó Szilárd, discoverer of the chain reaction. It contained a critical mass of fissile material, together with control rods, and was built as a part of the Manhattan Project by the University of Chicago Metallurgical Laboratory. Chicago Pile-1 (CP-1) was the world's first human-made nuclear reactor. CP-1 was built on a rackets court, under the abandoned west stands of the original Alonzo Stagg Field stadium, at the University of Chicago. The first self-sustaining nuclear chain reaction was initiated in CP-1 on December 2, 1942.