The first atomic bombs tested and detonated in the United States (US) sparked a mass fascination with atomic technology in a period that came to be known as the Atomic Age. The widespread support of the atomic bombings in World War II (WWII) and approval of atomic weapons thus ignited accelerated testing of atomic weaponry. However, with the earliest nuclear weapons tests, the American military paid little attention to the potential consequences of the tests. This paper examines the nature, impact, and implications of two of the major twentieth-century American atomic tests: Crossroads Baker and Castle Bravo. These tests led to serious health repercussions for both native Bikini Islanders and American servicemen involved with the tests. The American government’s reckless approach to nuclear testing in the first part of the twentieth century was not only disastrous in terms of the health issues it created but was also unethical due to its misleading warnings. The environmental and health effects of the US government’s negligent actions then can still be felt today — nuclear waste from the tests remains locked up with little maintenance at the Enewetak Atoll, threatening another potential nuclear disaster due to mismanagement and negligence.