Well, you didn't have to be non-American to work in Hamilton, just non-white.
"The producers of the Broadway musical "Hamilton" issued a casting call specifying "non-white" actors for auditions."
Hamilton, the Tony-winning Broadway musical that retells the story of the United States’ founders with a multicultural cast and a hip-hop score, attracted unwanted controversy in March 2016 when its producers issued a casting call specifying “NON-WHITE men and women” actors for ongoing and future productions of the show.
The advertisement came to the public’s attention after a prominent civil rights attorney, Randolph McLaughlin, questioned the legality of its wording.
CBS News reported:
“What if they put an ad out that said, ‘Whites only need apply?’” said McLaughlin, of the Newman Ferrara Law Firm. “Why, African-Americans, Latinos, Asians would be outraged.”
McLaughlin believes the ad violates the New York City Human Rights Law, which makes it unlawful “for an employer… because of the actual written or perceived… race of any person, to discriminate.”
“You cannot advertise showing that you have a preference for one racial group over another,” McLaughlin said. “As an artistic question – sure, he can cast whomever he wants to cast, but he has to give every actor eligible for the role an opportunity to try.”
That is also the policy of Actors Equity, the Broadway union, which says, “…producers agree that auditions for all productions… will be conducted in such a manner as to provide full and fair consideration to actors of all ethnicities.”
Though the producers of Hamilton maintained that the ad had been approved by Actors’ Equity, the union’s general counsel said it had not and would not approve such language, the CBS report continued.
It is essential to the storytelling of Hamilton that the principal roles — which were written for non-white characters (excepting King George)— be performed by non-white actors. This adheres to the accepted practice that certain characteristics in certain roles constitute a ‘bona fide occupational qualification‘ that is legal.
https://www.snopes.com/fact-check/ha...-casting-call/