What is the title of Le Corbusier's 1937 book about the United States?

Le Corbusier’s 1937 book about the United States was titled When the Cathedrals Were White. The French original, Quand les cathédrales étaient blanches: Voyage au pays des timides, recorded his observations after traveling in the United States in 1935.

The book is part travel account, part architectural argument, and part cultural critique. Le Corbusier examined New York, skyscrapers, urban congestion, industrial production, public life, and American planning. He admired the energy and scale of the country while also questioning whether its cities achieved humane order and beauty.

The title is metaphorical rather than a reference to one specific American building. It evokes the pale stone of medieval European cathedrals and contrasts that legacy with the modern city. Readers sometimes confuse it with The Radiant City, his earlier urban-planning manifesto, or The Modulor, his later system of architectural proportions.