* No Official Census: The US Census doesn't collect data on ethnicity or ancestry in a way that would easily determine how many people identify as Persian.
* Variety of Identifiers: People of Persian descent may identify as Iranian, Persian, Farsi, or even just American. There's no single, universally accepted term.
* Immigration Patterns: The Persian diaspora in America is diverse, with immigrants and descendants arriving over different periods and from various parts of the world (not just Iran).
Estimates: Some sources provide estimates, but they are often based on limited data and can vary widely. For example, the Pew Research Center estimates that there were around 500,000 people of Iranian origin living in the US in 2013. However, this number could be higher or lower depending on how "Persian" is defined.
Bottom Line: It's impossible to say definitively what percentage of America is Persian. The answer depends on how you define "Persian" and what data you use.