Has there been any case on which all justices of the US Supreme Court disagreed?

Question

For cases decided by the US Supreme Court, one justice is tasked with writing the majority opinion, and if there is not unanimous support for the decision, then another justice is tasked with writing the dissenting opinion. Concurring opinions may be independently provided by justices who agree with the majority decision but not the reasoning presented in the majority opinion. I assume that the same is permitted for justices who agree with the dissenting decision but not the reasoning in the dissenting opinion.

Has there ever been a case that proved so divisive that every justice on the Supreme Court independently wrote and submitted a completely separate opinion? If so, how often has this happened? If this has never happened, then what case had the greatest number of independently submitted opinions?

Answer 1

In the case New York Times Co. v. United States, the court issued a brief per curiam opinion basically saying that the NYT won, and then each justice wrote a separate concurrence or dissent. A few justices did join each others' opinions, and in particular, Justice Harlan's dissent was joined by both of the other two dissenters (who also wrote separately). On the concurrence side of things, Justices Black and Douglas joined each other, and Justices Stewart and White joined each other.

The subject matter in this case was whether the New York Times was allowed to publish the Pentagon Papers; the United States government opposed this on the grounds that the documents were classified and (allegedly) a risk to national security.

This gives us a total of nine signed opinions plus one unsigned per curiam opinion, which is rather short and so I don't think it should count. The sole function of the per curiam was to prevent any one of the concurrences from being characterized as "the majority opinion."

Answer 2

I can't find 9, but I figured I'd chime in that abortion cases have been well known to split the court, with the highest number of opinions I could find being 7 or 8 depending on your definition.

Stenberg v. Carhart generated 8 distinct written opinions consisting of a majority opinion with five justices, three concurrences and four dissents. You could count this as 7 though, since Stevens & Ginsburg are in complete agreement, having joined the majority, each other's concurrences and none of the other opinions.

Both Roe v. Wade and June Medical Services, LLC v. Russo generated 6 straightforward opinions.

Planned Parenthood v. Casey created a complex split in the court, I'm just going to quote the syllabus for the detail (PDF link, pgs. 841-842):

O'CONNOR, KENNEDY, and SOUTER, JJ., announced the judgment of the Court and delivered the opinion of the Court with respect to Parts I, II, III, V-A, V-C, and VI, in which BLACKMUN and STEVENS, JJ., joined, an opinion with respect to Part V-E, in which STEVENS, J., joined, and an opinion with respect to Parts IV, V-B, and V-D. STEVENS, J., filed an opinion concurring in part and dissenting in part, post, p. 911. BLACKMUN, J., filed an opinion concurring in part, concurring in the judgment in part, and dissenting in part, post, p. 922. REHNQUIST, C. J., filed an opinion concurring in the judgment in part and dissenting in part, in which WHITE, SCALIA, and THOMAS, JJ., joined, post, p. 944. SCALIA, J., filed an opinion concurring in the judgment in part and dissenting in part, in which REHNQUIST, C. J., and WHITE and THOMAS, JJ., joined, post, p. 979.

Assuming I've understood correctly, that's 7 opinions filed. However, you could argue there's only 4 distinct lines of thought with Rehnquist-White-Scalia-Thomas all agreeing, O'Connor-Kennedy-Souter all agreeing and Blackmun and Stevens doing their own thing. Additionally you could consider it 5 if you're counting distinct written opinions but not counting Blackmun and Stevens's separate partial joining with O'Connor-Kennedy-Souter as distinct opinions.