Hello, this is my first post on Reddit, so cheers to whoever finds this! In the midst of finding ways of procrastinating studying for finals, I stumbled across a list of things "Americans" do that make others from different countries / cultures angry. One of the actions listed was that people from the states refer to their home as "America" instead of the "US". I was just wondering how the name "America" become synonymous with the US, in spite of the fact that there are 23 countries that make up North America, and another 12 in South America?
Because America is the only country actually called America. Insisting on calling it the United States is like calling Germany the Federal Republic (or Der Bundesrepublik, as you will), or calling China the People's Republic, or Saudi Arabia the Kingdom. The full official names are United States of America, Federal Republic of Germany, People's Republic of China, and Kingdom of Saudi Arabia, but it's generally understood that one part is the name and the rest is descriptive qualifiers.
Exception: The United Kingdom of Great Britain and Northern Ireland, I'm not qualified to do more than speculate on why we call it the United Kingdom as opposed to Britain and Ireland, save that the latter is kind of wordy.
Now, it's certainly unusual for the country to share the same name as the continents, but it happens to be the way it is. While originally just a descriptive name (the United States that happened to be on the landmass called America), the name ended up adopted as the name of the country as early as January of 1776 (unofficially, the earliest official use of the name I'm familiar with is June of 1776, in a draft of the Articles of Confederation).