Maybe you've already seen this, but in case you haven't, description
from a fragment of a letter to his sister, summer of 1853:

"...from a gallery (second floor) you have a glorious sight--the flags
of different countries represented, the lofty dome, glittering
jewelry, gaudy tapestry, &c., with the busy crowd passing to and fro--
tis a perfect fairy palace—beautiful beyond description.

 The Machinery department is on the main floor, but I cannot
enumerate any of it on account of the lateness of the hour (past 8 o'clock).
I
would take more than a week to examine everything on exhibition; and
as I was only in a little over two hours tonight, I only glanced at
about one-third of the articles; and haing a poor memory; I have
enumerated scarcely any of even the principal objects. The visitors to
the Palace average 6,000 daily—double the population of Hannibal. The
price of admission being 50 cents, they take in about $3,000."

--The Complete Letters of Mark Twain, pp12-13


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