Far more people came to Expo 67 than expected, at a time when Canadas entire population was just 20 million, and the islands were more than just a fairground. They were a cosmopolitan pleasure garden, a place to see and be seen. The swankiest Expo denizens were the 1,800 or so pavilion hostesses, kitted out in polyester or lam uniforms and hired for more reasons than just bilingualism. (Montreal is generally known for its attractive women, a male CBC broadcaster intoned in 1967, but this year the situation has become ridiculous.)

Expo 67s subtitle was Man and His World, an English approximation of the title of Saint-Exuprys Terre des Hommes. The place of women at the fair, and the expression of modernity and national ambitions through clothing, is the subject of Fashioning Expo 67, on view at the McCord Museum downtown. Mannequins display Bill Blasss mod uniforms for hostesses at the American pavilion: a white tent dress with a red-white-and-blue head scarf, plus a killer striped raincoat. At the Quebec pavilion, the attendants wore bulbous cloches, while the Brits toted Union Jack handbags; newly independent African nations went for more traditional designs and wax fabrics. Throughout the Expo, hostesses wore pale blue A-line skirts, blazers and pillbox hats. (Over at MAC, the artist Cheryl Sim wears one of these sky-blue uniforms in a contemplative three-screen video, in which she sings a melancholy remix of the Expo theme song Un Jour, Un Jour.)

The futuristic fashions had a counterpart in the Expos architecture, entrusted to young, experimental engineers and backed by budgets unimaginable today. Many made use of industrial materials and modular construction techniques above all, Frei Ottos West German pavilion, whose swooping tensile roofs were reprised at the 1972 Munich Olympics. The Expos most lasting architectural project was not a pavilion at all, however, but an experimental housing development. The Israeli-Canadian architect Moshe Safdie, then just 28, proposed a new mode of living that married urban density and suburban spaciousness, in the form of concrete cubes stacked like building blocks. Habitat 67 was initially imagined as a self-contained community, similar to the superblocks of Braslia, which could be endlessly repeated. It became upper-middle-class condos, and when I walked past Habitat this week, residents were sunning themselves on the balconies while gardeners buzzed the grass. (Mr. Safdies designs and models are now at the Centre de Design de lUQAM, a university art gallery downtown.)

Many cities have gained an iconic structure from their days hosting the world: the Eiffel Tower in Paris, the Space Needle in Seattle, the Atomium in Brussels. Montreals legacy, along with Habitat, is a massive geodesic dome on le-Sainte-Hlne, designed by Buckminster Fuller, which served as the American pavilion in 1967. Inside were paintings by Warhol, memorabilia from Elvis and Hollywood, and space capsules from the Apollo and Gemini programs, but it was Fullers pavilion itself, pierced in two spots by a monorail track, that enthralled fairgoers most.

At MAC, the Canadian artist Charles Stankievech has assembled a bulging archive of materials that limn the contradictory aims of Fullers dome, as indebted to American military ambitions as to Spaceship Earth environmentalism. But I decided to head out to the island, where Fullers dome gleams beneath the sun. The acrylic panels went up in flames in 1976, and the dome sat vacant for years. Its since been rechristened the Biosphre, and the museum inside hosts exhibitions on the natural world and climate change though, for the summer, a temporary exhibition, Echo 67, includes testimonials from Expo visitors and a small display on environmental impact.

As the clouds went by, and the maple leaf flag fluttered beneath Fullers awing, column-free expanse, I found myself overcome with a feeling I dont often confront when I look at the art of the recent past. That feeling was envy an envy of the certainty in cultural and social advancement felt by the millions who passed across this island, and an envy shared, I think, by many of the artists in MACs exhibition. Its one thing to identify the gaps in Expo 67s narrative, to call out its sexism and nationalism. Harder, and more urgent, is to admit why artists are still infatuated with past visions of the future that didnt come true. We would give anything to believe in progress again.

In Search of Expo 67 Through Oct. 9, Muse dArt Contemporain de Montral, macm.org.

Fashioning Expo 67 Through Oct. 1, McCord Museum, musee-mccord.qc.ca.

Echo 67 Through Dec. 17, Biosphre, ec.gc.ca/biosphere.

Expo 67 A World of Dreams Through Oct. 8, Stewart Museum, stewart-museum.org.

Habitat 67: The Shape of Things to Come Through Aug. 13, Centre de Design de lUQAM, centrededesign.com.

A version of this article appears in print on June 23, 2017, on Page C13 of the New York edition with the headline: Utopia: The Reboot.

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Expo 2017: Utopia, Rebooted - New York Times