The Manhattan Project was a pivotal research and development initiative during World War II that led to the creation of the first nuclear weapons. Officially launched in 1942, this top-secret project involved collaboration among scientists, engineers, and military personnel, primarily in the United States but also including the United Kingdom and Canada. The project culminated in the successful testing of the atomic bomb in July 1945 in New Mexico, known as the Trinity Test. The subsequent bombings of Hiroshima and Nagasaki in August 1945 ultimately resulted in Japan's surrender, thus marking a significant turning point in the war and the onset of the nuclear age.