/lit/ - Literature

>>18390331
This is a part of the answer. The entire Transcendentalist movement RW Emerson started with "Nature" is arguably the first authentically American metaphysical school (although it's deeply reliant on Platonism/Vedanta). Whitman was the first, however, to actually live up to what Emerson was suggesting people do and write his own Scripture. Pic Related goes into detail on it.
(also, look into Mel Lyman if you want to see the Yang to Charles Manson's yin)