High Quality Content by WIKIPEDIA articles! Trinity was the code name of the first test of a nuclear weapon. This test was conducted by the United States Army on July 16, 1945, in the Jornada del Muerto desert about 35 miles (56 km) southeast of Socorro, New Mexico, at the new White Sands Proving Ground, which incorporated the Alamogordo Bombing and Gunnery Range. (The site is now the White Sands Missile Range.) The date of the test is usually considered to be the beginning of the Atomic Age.