Los Alamos Historical Society Online Teacher's Guide

The Los Alamos Laboratory was conceived during the early part of World War II. The United States wanted to build an atomic explosive to counter the threat posed by the German nuclear development program. The federal government used its powers of eminent domain to take over the homesteads on the Pajarito Plateau for the Manhattan Project in 1942. Officials felt the Los Alamos Ranch School buildings would supply adequate housing for the estimated 30 scientists who would work on the project. (Little did anyone at the time realize the town would grow to more than 6,000 residents during the war.) Physicists, chemists, metallurgists, explosive experts and military personnel converged on the isolated plateau. Meanwhile, the Army was charged with supporting the work, building buildings, keeping the commissary supplied, and guarding the top secret work.

The obstacles that had to be overcome and questions that had to be answered before an atomic bomb could be built were numerous. Many even wondered whether the “gadget,” as it was called, would work. The scientists worked feverishly in fear that the Germans were developing a nuclear weapon and would have it ready before the United States.

Finally, on July 16, 1945, at 5:30 a.m., an incredible burst of light exploded over the desert in south central New Mexico. Trinity, as the test shot was known, answered many of the questions the scientists had been asking. An atomic bomb was dropped on Hiroshima on August 6 and another on Nagasaki on August 9. Five days later, the Emperor of Japan agreed to an unconditional surrender. The Manhattan Project, a mission to end the war through the use of atomic weapons, had accomplished its goal.