Share 'Transition from the gourd'

I'm afraid this might end up being a stupid question but..... I'm trying to put together a short paragraph history of the early development and mass popularity of the banjo.   Was Sweeney the first to make a banjo that was not a gourd?  If minstrels were supposedly imitating slave life, what was the motivation to change the gourd "banjo" into the banjo constructed/played by Sweeney and other mins…