Note how I don't call the United States by the term "America". This is not America, America covers everything from Canada down to Argentina.
In most senses, people use "The Americas" to refer to the continents, and America to refer to The United States of America. This does not make us ignorant. After all, we refer to ourselves as "Americans" - not as United Statesians. I am not saying that other residents of North America, South America and Central America aren't "American" in that they live in The Americas, but each country has its own designation for nationality.