cast-iron architecture, a term used to designate buildings that incorporate cast iron for structural and/or decorative purposes. After 1800 cast-iron supports were exploited as an alternative to masonry, and with the introduction of wrought-iron beams at mid-century, an efficient, prefabricated method of skeletal construction was possible, of which the most notable example was Joseph Paxton's Crystal Palace (1851) in London. Iron and glass canopies were used to cover such diverse structures as shopping arcades, library reading rooms, and the vast new railway terminals. In the United States, James Bogardus pioneered the use of cast-iron commercial facades, which combined utility with the easy replication of attenuated classical orders in repeated bays.