MONTREAL — It didn’t seem very Canadian.

For Expo 67, this usually modest and frugal country spent vast amounts of money to create islands within the St. Lawrence River and build an array of huge buildings, all to show off Canada to the world.

But even if uncharacteristic, the fair was a coming out for a new Canada. And in 1967, it defined the country’s celebration of its 100th birthday (or, more accurately, the centennial of its current political structure) in a way that no single event will mark the 150th on Saturday.

Much like today, 1967 was a time when Canada was reimagining itself. Its now iconic maple leaf flag was only two years old, and a committee was recommending that “O Canada” succeed “God Save the Queen” as the official anthem.