At a time when most New Yorkers lived in fairly modest quarters, the American Museum was impressive for its large public spaces. Patrons would pay an admission of 25 cents and could wander through the building, visiting the various displays or attending shows and lectures.
Nearly everything in the museum was eventually destroyed in a colossal fire, so it's only possible today to know what was on display by referring to advertisements for the museum, or accounts by visitors. And it's unclear, of course, how many of the wondrous artifacts on display were genuine, or examples of Barnum's famous "humbug," the term he used to describe exaggerated claims.