Get the hell out of Dodge is was a catchphrase, turned into an idiom during the second half of the 20th century.
It is used synonymously to the word “scram” meaning to leave a place in great haste.
The phrase comes from the Western movies of the early 20th century, in which Dodge city, Kansas had been a reoccurring location, turned cliché.
In these motion pictures, the villains were often given the order; “Get the hell out of Dodge!”
The later generations had turned the catchphrase into an idiom, using it to indicate the right time to just get the hell out of some place.
It had spread all across America in the late 1900’s and had turned into a cultural heritage of that generation.
The idiom had been defined on Urban Dictionary in 2005, informing the ignorant of the meaning of this expression.
While it is not as widely encountered nowadays, it is still a remnant of an age past, brought up by the ghosts of yesterday.