The Manhattan Project The Manhattan Project was and is still one of the most secretive projects ever created in United States history. The purpose of the Manhattan Project was simple: to build; test; and unleash its power if necessary. Robert Oppenheimer and General Leslie Groves were the two men put in charge of this mission. These two men along with the top scientists from around the country were brought together to construct the most deadliest thing known to man. The project originated in the Pentagon in 1942 when General Groves was told, by the White House, he was to lead the Manhattan Project. World War II h