Not Jerome David.

9. Raoul Peck made a documentary about me called "I Am Not Your Negro." It was based on my personal recollections of MLK, Medgar Evers and Malcolm X.

10. The funniest part of my FBI files were the "documents" about my wife, Mrs. ______. I was never married. In fact, I'm gay.

The name of that documentary rings a bell. I think I saw it or a clip of it and I remember the fella but not his name.

11. My novels include Go Tell It On The Mountain, Another Country, and Giovanni's Room.

I consider myself to be fairly well-read. However these are three fine books that sit very comfortably of the list of books I have not read.

Last clue:

12. Non fiction: Notes of A Native Son, and The Fire Next Time. On YouTube you can see why I won my famous debate before UK Cambridge students with conservative William F. Buckley Jr., debating civil rights for African-Americans.

W.E.B. Du Bois

Close. I'm out of clues: James Baldwin.

Whoever wants to go can take it.

Had to Wikipedia him. Interesting character!

1. I was born in 1926 in New York City
2. My father worked for the family securities firm
3. Dad traveled a lot for work, so I was raised mostly in southern states.

Marilyn Monroe?

Not Marilyn...

4. After an uneventful high school experience, I served my country by enlisting in the U.S. Navy. During World War II, I served on a submarine chaser.

5. I had a brother and sister. Both died young.

6. After being discharged I went to college on the G.I. bill. In 1952 I graduated from Harvard.

Jack Lemmon?

Nope, not Jack.

7. I soon found myself being cast in stage roles. Possibly because I am tall, I was cast as gangsters and as cops in different productions.

Fred Gwynne?

Sheldon Leonard?

Jack Palance?

Karnak, you munster, you've done it again. Fred Gwynne it is indeed!

8. I was married twice and had five children
9. My television career got started when I was cast as a guest on two episodes of the Phil Silvers show
10. I had great luck to be cast to star in two different TV series that were both well received
11. People thought I had stopped working in the mid 70's through the early 80's but truth was I was doing guest shots and stage work. There were also a couple of reunion shows from one of my TV series.
12. Most people did not realize I can sing. I appeared in stage musicals as well
13. Starting in the later 80s I returned to the limelight in several high profile movies.
14. My last film was in 1992, ad it is probably the one I am best remembered for.
15. I died young, at 66 of pancreatic cancer and am buried in Maryland

In clue #7, the mention of "tall" and "cops" immediately made me think of "Car 54, Where Are You?"

Give me a minute to think of a candidate.