Reading up on the Baker v Carr Supreme Court case, I was struck by how many opinions were issued in that case. The decision was 6-2 (one Justice recused himself due to health). Besides the official opinion, there were three concurring and two dissenting opinions issued. That means six opinions from eight Justices.
Has there ever been a case where all Justices issued an opinion? If not, what’s the highest percentage?
Just a pre-emptive reminder that this is Factual Questions. We need not concern ourselves here with whether the opinions were “right”, “wrong”, “reasonable”, or anything of the sort. Who offered or co-signed what agreement is an objective matter of public record, and all we need concern ourselves with here.
Seems to be an answer to the same (or a substantially similar) question here:
In summary, in New York Times Co. v. United States, there were nine separate signed opinions, plus one unsigned opinion (really just a short statement) reporting the court’s overall ruling.
If you look closely at the linked page, you’ll see why I didn’t have to “find” it at all. 
Great minds question alike!
As an aside there is a podcast called “More Perfect” which looked into the Baker v. Carr Supreme Court case. I think it is fascinating. Well worth a listen. The case kinda killed two justices (only a little hyperbole…it really did ruin two of them).
When Chief Justice Earl Warren was asked at the end of his career, “What was the most important case of your tenure?”, there were a lot of answers he could have given. After all, he had presided over some of the most important decisions in the court’s history — cases that dealt with segregation in schools, the right to an attorney, the right to remain silent, just to name a few. But his answer was a surprise: He said, “Baker v. Carr,” a 1962 redistricting case.
Yes. At the beginning, the justices issued their opinion seriatim, meaning each justice would publish their opinion. Good article on it here.