Why Are American and Mexican Food So Different?

It is not news that the cuisine of America and the cuisine of Mexico are quite different things. Mexican food recipes, for example are certainly not very similar to those found in America. Strangely enough, Canadian food is rather similar to our own, as is often the case with neighboring countries - so why is the culinary tradition of our southern neighbor so different from ours? Mexican recipes use different ingredients than we commonly see in the average grocery store and create flavors, which seem exotic to American palates.