"American" is more confusing than "United States of America", I was also struggling to find out the option in the drop down menu. I had to search in Google why "United States of America" was removed from the list, then I found out this thread.
The option for your nationality is listed as American on the drop down menu. DW
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American is not a nationality, American( the american continent so everyone in the continent is american)...
Thanks. Twitter will use this to make your timeline better. UndoUndo
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