The Big Easy
Nickname for New Orleans, USA, referring to the easy-going, laid back attitude to life that jazz musicians and local residents indulge in there.
The origin of this is hard to determine. The name wasn't in common use until the publication of James Conaways' novel of the same name in 1970. Prior to that New Orleans was known as the Crescent City and some residents still prefer that nickname, viewing the Big Easy as a media-based import.
It's likely that Conaway picked up the name from existing slang. There are reports of a jazz club called the Big Easy, dating back to the early 20th century. Nevertheless, no evidence to substantiate those reports can be found. In fact, we can find no references to the term before 1970 that relate to New Orleans.
There's some link between this phrase and the Big Apple. The most plausible account of an origin for Big Apple is that it originated in the race tracks of New Orleans. It has been suggested that 'Big Easy' was coined in direct contrast to 'Big Apple', demonstrating New Orleans' more relaxed style.
Conaways' novel was used as the basis of a film that was released in 1987, also called Big Easy. The film, starring Dennis Quaid and Ellen Barkin, was a popular success and this was when the name came into the popular consciousness.