The United States of America. What a mouthful, right?
foreign dignitary: What country do you hail from, friend?
you: I am from the majestic land of The United States of-
foreign dignitary: zzzzzzzz
Here's a fun test to see if the name of your country is too long: Does your country have more letters than France. Yes? It is too long.
Hey, remember Kentucky Fried Chicken and how long that took to say so we just said KFC until the company went and changed it to KFC because it was the smart thing to do and it saved them ink on advertisements in the long run? How much could America save on ink by dropping that whole "The United States of" bit?
You may ask, "Why not just USA?" Then we'd still have to scroll to the bottom of lists of countries on forms, but America would be near the top.