Looks like a larger denomination Seated Liberty coin. There might be a way to tell which denomination, but no research allowed so I'll have to guess. I'm thinking it's a Seated Liberty Half Dollar, mid to late 1860's perhaps?
Certainly seated Liberty quarter or half.... What is it best known for? I would say seeing our nation through division, war and being reunited.
Is there an "extra fold" variety of seated liberty? Maybe I'm thinking of the shoulder fold / no shoulder fold Canadian QEII coins, or the drapery/no drapery thing.
Maybe the "What is this coin best known for?" has something to do with the small die crack? Maybe it's one of those 1861-O Half Dollars struck under the Confederacy?
Arrows, rays, no idea other than a Seated Liberty; I don't know enough about these older coins, on my list of things to learn though.
I am going to go with a seated liberty dollar. First silver dollar issued after several decades of not having silver dollars while smaller denominations were still being minted.
