Since when can U.S. citizens legally have only one name?
I would be surprised if there's any law prohibiting it. There are still places in the world where people only have one name and some of those people immigrate to the United States. I would be surprised if the law explicitly prevents them from having only one name.
Indeed. That would be a horribly discriminatory law.
And indeed there is no such law. A number of people in the US have legally changed their names to mononyms, including Cher, the magician Teller, and the wrestlers called Chyna and Warrior.
http://en.wikipedia.org/wiki/List_of_legally_mononymous_people
Basically, you can give yourself whatever name you want with only a few exceptions:
http://family.findlaw.com/marriage/how-to-legally-change-your-name.html
- You can't change your name just to escape debt liability or to hide from criminal liability.
- You can't change your name in order to commit a crime.
- You can't change your name with the intention to mislead. This usually involves taking the name of a famous person. Courts typically do not allow this, unless you have a convincing reason that is not related to the famous person or the use of his or her name.
- You can't choose a confusing nameone that includes numerals or punctuation. However, some courts have permitted people to spell out the numbers, for example "Seven" instead of "7".
- You can't choose a name that would intimidate, offend, or be considered obscene.
- You can't choose a racial slur.