How long have "pot" calls been around?

[ozarktroutbum]

I don't know the history behind pot style calls whether it's glass, slate, etc. Does anyone know how long they've been making them or who "invented" it?

[ol bob]

Not sure if he was the first but DD Adam from Pa. put them on the map around 1974.

[roverboy]

I've never heard who first made them but, I heard that the first pot calls were called that because of being made from flower pot bases.