Other presidents and their advisers have been more forceful about creating an opening on the court. In 1965, when President Lyndon B. Johnson wanted to put his friend Abe Fortas on the court, he persuaded Justice Arthur J. Goldberg, a Kennedy-era appointee, to leave the bench to take up an ambassadorship to the United Nations. Two years later, when Mr. Johnson wanted to appoint Thurgood Marshall as the first Black Supreme Court justice, he pushed Supreme Court Justice Tom C. Clark to step aside by appointing his son, Ramsey Clark, as attorney general, creating a potential conflict of interest.

The Breyer retirement lacks any similar drama.

When his departure was officially announced at the White House on Thursday, Justice Breyer offered a rare window into his thinking: As Mr. Biden stood behind him, he invoked the Gettysburg Address and spoke of the diverse and “complicated” country he had served. Respect for the Constitution and rule of law, he said, had made a complicated country an exceptional one.

Justice Breyer said that it would be up to future generations to shape the direction the country took from here. Those generations, he said, would “determine whether the experiment still works and, of course, I’m an optimist and I am pretty sure it will.”

It was really not so different from what Mr. Biden has said throughout his presidency. Earlier this month, he called for Americans “to stand for the rule of law, to preserve the flame of democracy, to keep the promise of America alive.”

And though Justice Breyer’s remarks were not political, many in Congress believed he had maneuvered to step down when Democrats were still in a position to replace him before the midterms.

Justice Breyer’s appearance at the White House on Thursday alongside the president was unusual. When Justice Sandra Day O’Connor retired, President George W. Bush delivered remarks alone in the Rose Garden after a phone call from her. Justice David H. Souter similarly placed a phone call to Mr. Obama, who announced the news in the White House briefing room. Justice Kennedy hand delivered his retirement letter to Mr. Trump but did not appear next to him that day.