‘‘Curtain wall’’ is mostly regarded as a direct outcome of the industrial reform in the Nineteenth Century. Following technological determinist approach, most of the studies about curtain wall seek to find an origin for it in the late Nineteenth Century. Different from these studies, this thesis investigates the formation of the discourse of curtain wall in view of its metaphoric background. Instead of focusing only on technology as the main factor, the study unveils different sides of the discourse which remained in the background and deciphers how ‘‘curtain,’’ a term borrowed from textile and theatre, has been associated with facade of frame structure. In detail, the study sheds light on how frame structure, one of the main components of a curtain wall system, came to be called as ‘‘skeleton’’ with reference to the theory of organicism. The dressing—Bekleidung—theory of Gottfried Semper is also examined as an alternative interpretation of the relationship between structure and facade regarding monumentalization through dressing and masking; as skeleton structure led architects to reconsider wall with concern of representation. Furthermore, the study concentrates on the architectural environment of Chicago in the second half of the Nineteenth Century, exploring two mainly different interpretations of frame structure which both arose from a shared concern of representation by some significant architects, including Louis H. Sullivan, who was also interested in monumentalization through ornament. This thesis claims that curtain wall is a metaphor invented to reconcile the emerging technology with the theory of representation which had diverse sides.