Very nice find Congrats! It is definitely a very old chair. You can tell by the slight crack on the back of the back rest due to dryness and the nail used. The caning of that chair is nice and in very good shape for an older chair like that, unless of course it had been re-caned at some point. It is made of Tiger maple also known as curly maple. This type of wood furniture reached it peak in manufacturing in the colonies during the 18th century. As for it being a Shaker chair, I am not really sure as it is more primitive in style? Could be a pilgrim chair perhaps? Either way, I would take it to an antique furniture appraiser as those can be work a LOT of money!