Expo 67 in Montreal was a gleaming futuristic spectacle. A monorail train snaked through the immense grounds. Pictured here, the Canadian pavilion along the St. Lawrence River. (National Archives of Canada, C-030085)

Montreal hosted the mammoth world's fair, revealing to Canada and the world the enormous economic and social transformation of post-war Quebec, dubbed the Quiet Revolution.

From the beginning, Prime Minister Lester B. Pearson worried that Montreal wouldn't meet the tight construction deadlines of the exposition. The fear of an unprecedented disaster hung in the air right until opening day; what if the country stumbled on the world stage?

But when Expo opened its doors on April 28, 1967, it was a gleaming futuristic spectacle. A monorail train snaked through the immense grounds that included oversized geodesic dome and an innovative housing complex called Habitat 67.

Sixty countries erected pavilions, from the sober to the fanciful, on two man-made islands in the St. Lawrence River, Île Ste-Hélène and Île Nôtre-Dame, created out of landfill from the building of the citys new subway system.

The Montreal Star described it as "the most staggering Canadian achievement since this vast land was finally linked by a transcontinental railway."

Expo 67 was sleek, sexy, and lived up to its theme, Man and His World. It was visited by more than 50 million people, a stunning international success.

Then French President Charles de Gaulle came to call and spoiled the party.

De Gaulle was one of many world leaders invited to Expo that summer. A hero from the Second World War, the President was ecstatically received in Quebec. His triumphant motorcade from Quebec City to Montreal, reminded De Gaulle of his glory days.

	On July 24, 1964, French President Charles De Gaulle (waving to crowd) stirred Quebec nationalist passions when he delivered the famous words from the balcony of Montreal City Hall: "Vive Montral ... Vive le Qubec ... Vive le Qubec libre!" (The Gazette and National Archives of Canada, PA-117531)

"All along the way, I found myself in the same atmosphere as that of the liberation."

On July 24, thousands gathered around Montreal's City Hall to greet De Gaulle. The President stood on the balcony flanked by Premier Daniel Johnson and Montreal mayor Jean Drapeau. He addressed the huge, enthusiastic crowd, delivering his famous words:

"Vive Montréal... Vive le Québec ...Vive le Québec Libre!"

Below him, the crowd erupted with cheers. In Ottawa, Pearson's reaction was diplomatic anger.

"Canadians do not need to be liberated," the Prime Minister said. "Canada will remain united and will reject any effort to destroy her unity."

De Gaulle cut short his trip and returned to France. But he had given Quebec indépendantistes like Pierre Bourgault an enormous boost.

"Because for the first time in 200 years he has come to our land to tell us in French what he thinks. He is the first man who is a winner to come and say to us: don't give up!"

De Gaulle's words also sent shockwaves through Quebec's political elite.

René Lévesque, a Quebec Liberal MPP, had watched the proceedings and pondered its consequences.

"A look at reality dictates that we should exercise as quickly as possible the right of any normal people which feels clearly that things don't work, that it is stuck at a crossroads, we must decide to use the right we have."

Lévesque left the provincial Liberal party a few months later, after his proposal for a modified form of independence, which he called "sovereignty-association," was defeated at the partys policy convention. Within a year, Lévesque would launch the separatist Parti Québécois, with a platform that outlined an economic union with Canada in the event that voters supported sovereignty.

In the fall of 1967, Canada's 100th anniversary celebrations wound down as Expo 67 closed its doors on October 28. Although the exposition was considered a huge success, the fateful day in late July had foreshadowed difficult times to come for the nation.