Serving under seven presidents, he forged his own path.
"When President Ford was faced with a Supreme Court vacancy shortly after the nation was still recovering from the Watergate scandal, he wanted a nominee who was brilliant, non-ideological, pragmatic, and committed above all to justice, integrity, and the rule of law," said President Barack Obama. "He found that nominee in John Paul Stevens."
On the current closely divided Supreme Court, with five conservatives and four liberals, Stevens anchors the left wing. His impact on the law is broad. He provided a critical fifth vote to:
• Affirm abortion rights
• Uphold affirmative action
• Ban the death penalty for juveniles
• Limit presidential war powers
Three years ago, when Crawford was at ABC News, Stevens granted her his only network interview. He insisted he was the same conservative Republican Gerald Ford nominated.
"I don't really think I've changed," Stevens said. "I think there have been a lot of changes in the court."
Born into wealth and privilege in Chicago, Stevens is a lifelong Cubs fan. He is known for his trademark bow ties and polite Midwestern manner.
"This is a country in which people can disagree without being disagreeable," Stevens said. "I try not to be disagreeable in my opinion writing and I think for the most part I succeed."
He is also fiercely independent. When the justices put on their robes before taking the bench, tradition calls for an aide to assist them. But not Stevens. He is the only one who refuses help - he does it himself.
But the courtly justice also can be harsh. He wrote a scathing dissent in Bush v. Gore, sharply criticizing the court's decision to stop the Florida recount, saying the decision would damage the court.
"Although we may never know with complete certainty the identity of the winner of this year's presidential election, the identity of the loser is perfectly clear," Stevens wrote. "It is the nation's confidence in the judge as an impartial guardian of the law."
In a letter, Stevens notified the White House this morning. Sources say the leading contenders to replace him are Elena Kagan, former dean of Harvard Law School and the current Solicitor General, Diane Wood, a Chicago Federal Appeals Court judge, and Merrick Garland, a Federal Appeals court judge in Washington, D.C. who is considered more moderate on criminal issues.
The president hopes his choice to be a lasting legacy - just like John Paul Stevens. The president said Stevens couldn't be replaced, but he'd try for someone with his wisdom and experience.