The people who built the Chrysler Building and danced through the 1920s never called their style Art Deco. They said style moderne or modernistic, and the label only took hold after a 1966 retrospective at the Museum of Decorative Arts in Paris and a 1968 book by historian Bevis Hillier. This episode traces how reinforced concrete freed architects from thick load-bearing walls, starting with Auguste Perret’s Theatre des Champs-Elysees in 1913, which one critic mocked as a zeppelin. Designers then mixed Cubist geometry, the wild colors of Fauvism and the Ballets Russes, Mesopotamian ziggurats, Mayan ruins, and the 1922 opening of Tutankhamun’s tomb.

It all came together at the 1925 Paris Exposition Internationale des Arts Decoratifs et Industriels Modernes, where historical styles were banned and France set out to reclaim the luxury market from cheaper mass-produced goods. Emile-Jacques Ruhlmann wrapped furniture in ebony, ivory, tortoiseshell, and sharkskin, and Le Corbusier answered with the house as a machine for living. The 1929 crash settled the argument, pushing the style into Streamline Moderne, with aerodynamic curves on cars, clocks, radios, and even refrigerators, and into WPA murals of postal workers and farmers.

• Why reinforced concrete, combining compressive and tensile strength, made soaring setbacks and open interiors possible
• La Maison Cubiste of 1912, which put prismatic Cubist shapes onto staircases, wallpaper, and furniture
• The 1925 exhibition’s scale: 55 acres, 15,000 exhibitors from 20 countries, and 16 million visitors
• A Ruhlmann bed that cost more than an average house, and Paul Follot’s defense of the superfluous
• Diego Rivera’s 1933 Rockefeller Center mural, destroyed after he refused to paint over Lenin