I hesitate to jump into this panorama discussion with something completely
tangential to the subject.  However, I will.  Out in the middle of Australia
(Alice Springs) they have a panorama called Panorama Guth (the artist's
name)
that is in a domed room.  In the middle is a "desert" of real sand and
desert
plants and stuff.  around that, (concentric circle) is a walkway where you
stand
and walk. Around that, a small fence to keep you from the painting itself.
The painting is a series of panels brightly lit, that--when you walk
all the way around--conveys the sense of being out in the Aus'n big sky.
There's not really anything "in" the pictures, like houses or even animals,
but just the sense of looking out over the desert in a 360 degree panorama.
   Pretty astounding experience.  No doubt, the Mississippi panoramas were
intended to (and may have) convey(ed) a similar feeling.
   Twain would have loved them both!