"I’ve been surprised by the intensity of the Meryl Streep loyalty."

There were, but they were in separate, not equal, businesses.

There were 'race' films from the very beginning of the medium.

Explore the Flickering, Forgotten Past of African-Americans in Silent Film | Smart News | Smithsonian Magazine

And even setting aside Al Jolson (Asa Yoelson) and The Jazz Singer, Yiddish film was a pretty vigorous extension of Yiddish theater until the run-up to the second World War.

Which was kind of interesting in itself, because all the major studios - first in New York, then in Hollywood - were founded and run by assimilated Jews. Neal Gabler's An Empire of Their Own is a good read on the subject.

As to the other question, the use of 'actor' and 'actress,' those distinctions arose and then changed only recently, almost entirely as a function of the politics of language.