Okay, so you don't read so well. I said *nation*, not *continent.* There is no nation of North America, Central America, or South America. Those are *continents.*
There is *one country* that has 'America' in its name; the United States of America. That's why people from here are... Americans. People from Canada, for example, are Canadans. People from Mexico, OTOH, are Mexicans. We're not all 'North Americans', because 'North America' isn't a country.