On June 17, 1942, President Roosevelt signed off on a $90 million research proposal from a team of scientists and military personnel to pursue research, design, and the testing of the world’s first nuclear bomb as part of the Manhattan Project. By June 1944, the project employed around 129,000 workers, most of whom were construction workers, plant operators, and military personnel. Over the course of the project, chemists and physicists would pursue five different techniques, numerous design concepts, and eventually settled on a method that led to them conducting the first ever nuclear explosion, codenamed 'Trinity', on July 16, 1945. The explosion created an energy equivalent of around 20 kilotons of TNT, left a crater 250 feet wide, created a shock wave felt over 100 miles away, and produced a mushroom cloud 7.5 miles high.
