But what kind of construction would have succeeded it?   Really, the balloon frame? Balloon or platform, although it's my understanding that balloon preceded platform   Just like the diagrams in my 6th grade American history textbook about Conquering The West?   Or some other kind of frame?   How is Gracie Mansion constructed? No doubt post and beam of some sort. Morris-Jumel?  Ditto. This is what the carpenters knew how to build, and until they needed something faster and cheaper, they kept doing it the same.  Unless Rudy says otherwise.