The Manhattan Project was a secret research and development program during World War II aimed at creating the first nuclear weapons. Initiated by the United States with support from the United Kingdom and Canada, it began in 1942 and involved some of the world's top scientists, including J. Robert Oppenheimer and Enrico Fermi. The project culminated in the successful testing of the first atomic bomb in July 1945 at the Trinity Test site in New Mexico. The project led to the development of two types of atomic bombs, which were dropped on the Japanese cities of Hiroshima and Nagasaki in August 1945. This action played a significant role in bringing about the end of World War II. The Manhattan Project also marked the beginning of the nuclear age, raising ethical and political questions about the use of nuclear weapons that continue to be relevant today.