But Mr. Martin did not really rate in the singular world of Washington celebrity, and spectators instead pointed excitedly at Senator Patrick J. Leahy, the chairman of the Senate Judiciary Committee.
President Obama and Vice President Joseph R. Biden Jr. also attended, along with lawmakers, federal judges, Justice Department officials and members of Justice Sotomayor’s family.
The ceremony was a formality: the new justice was confirmed and sworn in last month. But it had a certain pomp. Justice Sotomayor was, for instance, initially seated facing the bench in a chair that had been used by Chief Justice John Marshall.
Attorney General Eric H. Holder Jr. made a motion to have the clerk of the court read Justice Sotomayor’s presidential commission. Chief Justice John G. Roberts Jr., without particular deliberation, granted the motion.
The commission, in elaborate legalese on impressive parchment, was duly read. It said Justice Sotomayor possessed “wisdom, uprightness and learning.”
After the chief justice administered the judicial oath, Justice Sotomayor took her seat to his left on the far side of the bench, the spot reserved for newcomers.
The ceremony was over in four minutes. A photo opportunity on the steps in front of the court followed, and it lasted about twice as long.
Chief Justice Roberts and Justice Sotomayor chatted at the top of the steps, outside of reporters’ earshot. Then they walked down the steps, chatted some more and shook hands. Justice Sotomayor stood by herself for a while, ignoring questions shouted in Spanish and English.
“Tell me when you’ve had enough,” she said to the photographers.
She was joined by members of her family for more photos, receiving a long hug from her mother. “Bye, guys,” she told the photographers as she left.
Opening Day
The real work begins on Wednesday, when Justice Sotomayor will hear her first argument, at an unusual summer session of the court. The case, Citizens United v. Federal Election Commission, is important, but that is not the only thing that has aficionados of oral advocacy in the Supreme Court buzzing.
“It’s like an all-star game for court fans,” said Pamela Harris, executive director of the Supreme Court Institute at Georgetown University Law Center.
“You’ve got the great veteran Supreme Court advocates, the First Amendment legend, the first argument of the first woman solicitor general — and on the bench, Justice Sotomayor’s first oral argument,” Ms. Harris said. “That’s an incredible combination.”
Citizens United, a conservative advocacy group that lost a lawsuit seeking to show a documentary critical of Hillary Rodham Clinton on cable television during last year’s presidential primaries, is represented by Theodore B. Olson, a solicitor general in the administration of George W. Bush who has argued more than 50 cases in the court.
In one of them, Mr. Olson successfully defended the statute he is now attacking, the McCain-Feingold campaign finance law. Switching sides is unusual but not improper, and Mr. Olson said the government had told him it had no objection to his new role.
Arguing alongside Mr. Olson will be Floyd Abrams, who represents Senator Mitch McConnell of Kentucky, the Republican leader and a longtime foe of campaign finance laws. Mr. Abrams has argued more First Amendment press cases in the court than any other lawyer in history.
On the other side, representing the federal government and defending the law, is the new solicitor general, Elena Kagan, a former dean of Harvard Law School. Ms. Kagan will be making her Supreme Court debut.
She will be joined by Seth P. Waxman, a solicitor general in the Clinton administration, who also has more than 50 arguments under his belt. He represents Congressional sponsors of the McCain-Feingold law.
In an interview, Mr. Olson said he was honored to be present for the first argument before a new justice and in such distinguished company. He and Ms. Kagan have something in common, he added.
“She’s nervous,” he said, “like all of us are before an argument.”
Fall Fashion
Then there is the question of what Justice Sotomayor, the third female justice, plans to wear. The investiture ceremony provided an important preview.
In interviews with C-Span released last week, the court’s first two female justices offered some implicit advice to Justice Sotomayor.
“I didn’t know anyone who made robes for women justices,” Justice Sandra Day O’Connor, who retired in 2006, said of the fashion problems that confronted her when she joined the court in 1981. “Most of what was available was something like a choir robe or an academic robe.”
The solution, Justices O’Connor and Ruth Bader Ginsburg both said in the interviews, excerpted from a series of programs on the court that will begin on Oct. 4, is to add a feminine judicial collar. And both said they had had to turn to foreign sources to find one.
“I discovered that the only places you could get them were in England or France,” Justice O’Connor said.
Justice Ginsburg pulled an item from her closet to show C-Span. “The robe is from England,” she said, “but the collar is from Cape Town, South Africa.” Consultation with a newsroom colleague revealed that the collar, which is circular and white, appeared to be made of crocheted lace.
On Tuesday, Justice Sotomayor wore a more elaborate collar, which also featured a rectangular flap of starched white fabric. Kathleen Arberg, the court’s public information officer, said it was a jabot (pronounced zha-BO), spelling the term for a cluster of reporters. It was made in Quebec, Ms. Arberg said, and was a gift from Justice Ginsburg.