Canada was founded by the French in 1534.
At the height of French power in North America, they owned most of the continent:
Link - http://upload.wikimedia.org/wikipedia/commons/f/f1/NouvelleFrance-Vraie-Version.png
Following a series of colonial wars, Britain took full, formal control of Canada in 1763.
With Britain and France being Canada's founding nations, Canada's two official languages are (naturally and understandably) Canadian English and Canadian French.
Because the majority of French Canadian settlers remained in Canada after the British conquest, Canada's home to the world's largest French speaking population outside France itself.
Canadian school kids are given basic French language instruction, but few ever continue with it past what's required for school to become bilingual.
Link - http://www.ocol-clo.gc.ca/html/act_loi_e.php
America, meanwhile, began as 13 colonies founded by Britain which later rebelled to create the United States.
In the 1800s, the US gained Spanish-speaking territory following wars with Mexico and Spain.
The US gain significant amounts of land as a result of its war with Mexico:
Link - http://wiki.answers.com/Q/What_land_did_the_US_gain_as_a_result_of_the_Mexican-American_War
And that included their Spanish speaking populations as well.
Unlike Canada however, the US has never passed any official language legislation designating anything as the official language(s) of the United States.
Plus in more recent times, immigration to the US from Spanish speaking countries (Mexico + Central and South American nations) have seen a tidal wave of illegal migrants into the US.
While nobody knows the exact number, estimates put it at over 11 million.
In other words: more than 3 three times New Zealand's entire population.
Of course New Zealand doesn't have French or Spanish as a second language.
You folks have Maori as your de facto second language.