Canadians of a certain age may still remember a time when their nation’s flag bore not the maple leaf, but the Cross of St. George present on the UK’s “Union Jack” flag. The cross on the canton, in the upper left quarter, was surrounded on all sides by a monochrome red symbolizing the same patriotic themes as the red stripes do on the American flag. This “Red Ensign” flag was the de facto flag of the 13 colonies, and the national flag of Canada for long after its independence.

On this day, February 15, in 1965, the Maple Leaf flag replaced the Red Ensign as the official flag of Canada. The move came after much debate, and is still not widely accepted – the provinces of Manitoba and Ontario continue to use the Red Ensign, with their own province’s coat of arms, as their official provincial flag.

The Great Canadian Flag debate centered around the inclusion (or not) of British symbolism in their own flag. Conservatives and Liberals in the Canadian House of Commons politicked fiercely: when the Liberals voted to accept the maple leaf design, the Conservatives launched a filibuster. It took six weeks and a vote of cloture to bring the embittering debate to an end.