The In Crowd

Does anyone know the origin of "The In Crowd"?

Don't know about origin exactly, but people who are "in" are usually in some important list, such as the Social Register, the A-list, the list of "beautiful people," the list of "cool people," in short, some celebrity list. They are the people who don't have to wait in line, as at, for instance, a noted restaurant or night club or disco or the opening of some event (the line is precisely what they are NOT in). SS

Also a song first by Bryan Ferry then by the Mamas and Papas:

I´m in with the "in" crowd
I go where the "in" crowd goes
I´m in with the "in" crowd
And I know what the "in" crowd knows (how to have fun!)
Any time of the year, don´t you hear? (how to have fun!)
Dressin´ fine, makin´ time
We breeze up and down the street
We get respect from people we meet
They make way day or night
They know the "in" crowd is out of sight
I´m in with the "in" crowd
I know ev´ry latest dance
When you´re in with "in" crowd
It´s easy to find romance (and we work out!)
At a spot where the beat´s really hot (and we work out!)