The first nuclear bomb was tested in 1945. Anything that is considered to be a trinity test has to do with nuclear weapons. This test was done in a desert in New Mexico. These places in the deserts that test nuclear bombs are called trinity sites. The testing site was built during the same year that they detonated the bomb. In order to get the war to stop, the government thought it would drop nuclear bombs on populated cities in Japan.
It looked like this war had gone on far enough. The war began in 1939 and the U.S. joined a little later. It ended after the bombings in Japan in 1945. It is believed that the U.S. would not drop any more nuclear bombs.