New York City was a pre-War city in the United States.
In 2065, a nuclear reactor, struggling to power the population of seventeen million people, went super critical for a period of about five minutes. While there was no explosion, the NYC incident coined the term "hot summer" for a heat-related electrical overload on nuclear systems.
New York City is mentioned in the Fallout Bible 0 and also in a Capitol Post article about the disbanding of the United Nations in Fallout 3. It is also mentioned in the Fallout: New Vegas add-on Dead Money, as well as Fallout 4, with the Statue of Liberty making a cameo appearance in the Atomic Command game.