[BobbyTables2]

I still never understood how we appropriated two whole continents.

If my name were “Bob of Idaho”, nobody would think Idaho meant only me. They would simply know I lived there.

Yes the United States are in the Americas, but it isn’t the entirety of them!

We have no more right to call ourselves “American” than Chileans do!

[sgift]

From my outsider perspective it's by being by far the most important country on the continent in terms of size, influence, economy and so on. Also, it's (afaik? cannot think of a counter-example) the only country which has America in its name and usually people talk about countries, not continents.