It's been a month since
The Laundromat was released on Netflix, and I'm updating Meryl's accent list to include her role of Elena in the film. I'm not interested in just brushing the film or the controversial subject of alleged "brownface" under the rug, so I'm adding it to the list. One caveat, however, is that the Latin(?) accent Streep dons for her second role has never been ascribed to a specific region or dialect. One would suspect that if Meryl did her typical due diligence, it would be something like Panamanian Spanish (as to my understanding, that's a specific sound).
I haven't heard Meryl say that she purposely didn't regionalize the character's sound (which if that's the case, only gives fodder to those who decry the generalization of her characterization). Nor have I heard her say that she intended to sound from a certain place. With that in mind, it's probably not accurate to say it's an "accent mastered," versus just sounding different from herself, which I like to catalog. Therefore, the updated list:
The Seduction of Joe Tynan (1979)--Tennessean
The French Lieutenant's Woman (1981)--British (specifically Received Pronunciation)
Sophie's Choice (1982)--Polish (in English and German)
Silkwood (1983)--Texan
Plenty (1985)--British (I think it's also RP)
Out of Africa (1985)--Danish
Ironweed (1987)--Irish-American
A Cry in the Dark (1988)--New Zealand (with strong layers of Australian)
The Bridges of Madison County (1995)--Italian (Meryl calls it Iowatalian)
Dancing at Lughnasa (1998)--Northern Irish
Angels in America (2003)--Yiddish and Bronx (in separate roles)
Prime (2005)--Manhattan (specifically Upper West Side)
A Prairie Home Companion (2006)--Upper Midwestern
Doubt (2008)--Bronx
Julie & Julia (2009)--Boston Brahmin
The Iron Lady (2011)--British (again RP)
August: Osage County (2013)--Oklahoman
The Homesman (2014)--Central Plains Midwestern
Suffragette (2015)--British (Received Pronunciation)
Florence Foster Jenkins (2016)--Mid-Atlantic
Mary Poppins Returns (2018)--vaguely Russian
The Laundromat (2019)--nondescript Latin (possibly Panamanian Spanish)