Is it unfair that the demonym "American" is generally applied only to people from the United States of America, but not to those of other countries in the Americas?

I don't really know why this came to be exactly.  All I can say is,...

I'm from Brazil and, therefore, from the American continent. And I honestly think that this insistence that "Americans are all of us, not just these arrogant guys from the US" is just unnecessary and stupid. They're called Americans because the country is the United States of America. Mexico is the United Mexican States and nobody complains they are called Mexicans! The same way Brazil was once Republic of the United States of Brazil and people were called Brazilians. It's not that of a big deal. Because of the fact that the American continent is so big, it is divided in three: North America, Central America and South America. So to refer to "Americans" as the people from the American continent, you can can call Mexicans, Americans and Canadians North-Americans, and Brazilians South-Americans. Therefore, leave the term "American" for the people of the USA. But let's say you can't take this because you think America is the entire continent. OK, so we have the same word for two meanings: American as being from the Americas and American as being from the USA. Let the context imply which one you're referring to, or simply clarify which one. Not that hard.

No.  I think this question is stilted.  The ONLY reason the United States' citizens are referred to as "Americans" is because the name of the country is "the United States of America" and giving us the demonym "Unitedstatsian" or "Unidian" or "Statsian" just sounds awful.  We opted for a demonym based on the last word of our nation:  American.  The world isn't any worse for wear because of it. There were early proposals for changing our national name to something more original, "United States of Fredonia", "United States of Columbia" (which would have put the thereafter Colombians in a pickle when they declared independence), and "United States of Appalachia" (which might have ceased being relevant after the US consumed its way across the continent).  Moreover, using terms like "fair" is a bit silly.  You make it sound like the poor, poor people of the Americas are suffering under this regime of American-name-hoarders.  When we refer to people from specific continents, we use the full continent's name:  "Asians", "Europeans", "North Americans" (incl. "Central Americans"), "South Americans", "Asians", "Africans", "Australians", etc.  When we refer to people "from the Americas", we typically say, "New Worlders", "Westerners" or -- if referring to the natives -- "First Peoples", "Native Americans", "American Indians" and "Pre-Columbian Natives". We're a creative lot, us human beings, we make do just fine and -- of course -- we have lots of names to describe peoples.  A word is just a word.  There is no "fair" or "unfair" in it.  When I travel the world, to Mexico, Brazil, Costa Rica, Venezuela, Spain, etc.  I never once heard people fretting about the naming scheme of Americans.  A few Spaniards used the castilian demonym "estadounidense" which -- to me -- perfectly fine (if a bit weird).  But in the Americas, none of the Mexicans or Venezuelans expressed any frustration about our demonym.  They typically said, "Norte Americano" or just "Americano" and that was that.

Let's take another country, say the United Kingdom of Great Britain and Northern Ireland.  But the people there are called generically British or English.   Is this offensive to other nations?  Do the inhabitants of Brittany in France feel offended by this fact and feel that this is a slight to their Breton blood?  Same thing with the Americans.  The United State of America is the only country with "America" as part of its name.  So calling us Americans is convenient, unambiguous, and should be as unoffensive as calling the inhabitants of the United Kingdom of Great Britain and Northern Ireland "British".

One should look into what makes up a demonym. A demonym is far more than an indicator of where one was born. The chosen demonym is a statement of the values, customs, and traditions of the populace. Some ethnicities refuse to be called by the official demonym of their country, opting instead for their ancestral demonym. Let us look at the demonym Mexican, which carries with it lots of baggage. A country, born out of the ashes of a thriving civilization, trampled under the horses of Spanish conquistadors. We are not Americans: America is the name the conqueror gave to our land. We are not Spaniards: in our veins runs the blood of Chichimecan warriors, Aztec priests, and Mayan astronomers. Our culture was birthed from the clash of two worlds. It is not purely native, nor exclusively European. We are Mexicans, people from the Moon's Navel, descendants of Cortés, Malinalli, and Cuauhtemoc alike. Compare now to the demonym American. The descendants of the first european settlers in the thirteen colonies regarded themselves, first and foremost, as Americans.  Among them were British, Scottish, Dutch, German, French, Irish and Italian settlers. Their life experiences, traditions, and mannerisms were different to those of the British and the inhabitants of the other New World colonies. Theirs was a culture purely of their own, shaped by the building of a new home in a strange, seemingly boundless land. If anything, the demonym American is fit only for them.

I am Colombian and I consider myself American.I resent the use of "American" only in Spanish. It's completely understandable that the evolution of the word has led to being used as a demonym in the USA. However, I feel different when it's in Spanish because:1. We have a perfectly good word for Americans: Estadounidenses2. For many of us America is the entire continent, from Canada to Argentina. America is subdivided in North, Central and South. The different definitions of the word can lead to misunderstandings.It might be stupid, but it matters to me and many others.

In English, "American" became the standard term for people living in Britain's North American colonies, or people from there.  (The grandfather of poet Percy Shelley was one example, returning to the homeland from a colony.)   It was also the logical common term for the thirteen colonies that came together, first to seek representation within the British Empire, then when this was denied to assert independence.  "American" was the only available term.  (Canada at that time was mostly French, but became a refuge for loyalists after Britain conceded independence.)   Had the 13 states become separate states, as happened with the Spanish colonies, they would probably just be identified by the names of those states.  (As does happen outside the USA for the better-known states, such as Texas and California, and regions like New England and the Mid-West.)   Brazil took some time to separate itself from Portugal, and I assume that by then the usage "American" for US Citizen was already entrenched.

Okay, so it is "generally applied" to the States, and?  It is an informal, unofficial term.  If someone from Columbia, for example, wants to refer to themself as an American, then more power to them, they have that right.  If they resent having to correct other peoples misconceptions, then maybe they should use a more exact term.

We need to reeducate about people’s identities! America is the name of one single country, and what you are depends on the "name" of your nation first; then after, you can use other adjectives to identify yourself.  British is a "United Kingdom" made of different nations from different parts of the world; so, nationals of countries pertaining to that kingdom are "British" citizens.  When referring to nationality, their identities are English, Welch, Scottish, Irish, etc.  Citizenship and nationality, are two different concepts. If you were born in any country, your national identity is derived from the name of that nation, either independent or controlled (dominated) and cannot be confused with your citizenship identity, which is derived from the name of a dominating government or kingdom.  You may say that your national identity is Hawaiian or Puerto-Rican (Although they prefer the term "Boricua"; but you are an "American" citizen, because the name of the country controlling or dominating is "United State of America".   We are very involved in this type of discussion, due to the fact that "Quisqueya", the nation I'm from, is only known b y its denomination of "Dominican Republic" and I cannot explain the reasons now; but a discussion around it may clarify a lot to those interested in knowing the different between national and regional identity; and then again, between them and citizenship identity.