I'm not sure the data would really support the assertion, but this BuzzFeed post lays out an interesting case for the number of British black actors who are winning serious roles — and awards season buzz — in American films and TV. In a way, it's similar to the number of white Australian actors who have been winning a lot of the best roles in American films for decades (though i have to admit, i always thought Thandie Newton was from Australia because i first heard about her in 'Flirting', with Nicole Kidman and Naomi Watts). I'd like to see some analysis on this topic because, strictly anecdotally, it seems to be a strong trend. On the other hand, Chadwick Boseman and Nicole Beharie are American actors winning serious roles so maybe the numbers don't really favor the British as much as the BF post might indicate. And, tbh, starting with 'Larry Crowne' and that old Kiefer Sutherland show 'Touch', I assumed Gugu Mbatha-Raw was American-born until I saw her amazing work in 'Beyond the Lights'. So, in the end, maybe it doesn't matter. Not unless you're an American actor with a SAG card trying to win one of a relatively small number of great roles every year.
In Selma, we find two of the most well-known and high-profile black Americans of all time getting the big screen treatment. Together, Martin Luther King Jr. and Coretta Scott-King became the poster couple for the civil rights movement, which promoted nonviolent protests in order to get inalienable rights for all Americans. In the film version, directed by Ava DuVernay, both roles are portrayed by black British actors; Carmen Ejogo, who has portrayed Scott-King once before (in an HBO film, Boycott), also is British.
"I'm sorry — they were just really good!" DuVernay mock-wailed in defense of her casting British actors during a recent interview with BuzzFeed News. "David is just an extraordinary artist. He is unlike anything I've come across in terms of his depth of his preparation, the openness of his heart with this part — totally sinking in and a desire to disappear into this, to give his whole self over to it. That level of commitment is the kind of thing you hear when you read Premieremagazine articles about Daniel Day-Lewis preparing. I would see it happen. And know how important it was to him. And to be a partner with him in this performance was just an honor, and at that point, you could be any nationality."
Still, there is something to be said for the technical training that many actors receive in England. Day-Lewis, who won an Academy Award for portraying President Abraham Lincoln in 2012's Lincoln, also is British. And in Selma, DuVernay cast Tim Roth, another Brit, to portray former Alabama Gov. George Wallace.