Seigenthaler began his journalism career in 1949 as a cub reporter for The Nashville Tennessean. He worked as a reporter and assistant city editor until 1960, when he took a job as administrative assistant to Robert Kennedy, who became attorney general in 1961 during the presidency of his brother.
While working for Kennedy, Seigenthaler served as chief negotiator with the governor of Alabama during the 1961 Freedom Rides organized by civil rights activists seeking to integrate interstate buses. During that crisis, he was attacked and knocked unconscious by a mob of Klansmen in Montgomery, Alabama, as he tried to aid a young protester who was being pursued by the rioters.
"I never saw anything in my life. Never will ever again to compare with the violence on that parking lot at that Greyhound station," Seigenthaler told The Associated Press in an interview in January.
"You don't see human beings acting like that," he added. "There were times when I'd go to a football game or a basketball game and the cheering got to me. It's not something you can live through and just put behind you, as if it didn't happen. It's tough. How can you take your children out to a race riot, and expect them to grow up as decent human beings?"
At a 2007 gathering, he joined others in taking a bus to retrace a Freedom Ride from Montgomery to Birmingham, Alabama.
"I'm going on this trip largely because I'm one of history's accidents. It was their vision and their courage that made the difference," said Seigenthaler. He called himself only "a footnote to the history of the Freedom Riders."
In 1962, Seigenthaler returned to The Tennessean as editor, but took a leave of absence in 1968 to help Robert Kennedy's presidential campaign.
The New York Times said he is "one of a handful of advisers in whom the senator has absolute confidence." After Kennedy was assassinated that June, Seigenthaler was a pallbearer at his funeral.
Back at The Tennessean, he added the title of publisher to his resume in 1973. And in 1989, he became chairman, publisher and chief executive officer.
Also in the 1980s, he became the first editorial director as the Gannett Co. launched USA Today. He held the post for almost a decade. Gannett also owns The Tennessean.
After he retired from The Tennessean in 1991, Seigenthaler founded the First Amendment Center at Vanderbilt. The mission of the center — an independent affiliate of the Arlington, Virginia-based Freedom Forum — is to create national discussion, dialogue and debate about First Amendment issues.
In July 2002, Vanderbilt named the First Amendment Center's building The John Seigenthaler Center. And in August 2001, the university created a scholarship for minority students in Seigenthaler's name after he gave Vanderbilt $2 million.
Seigenthaler said then that the scholarship would stand as a testimony that the cost of education is a worthy endeavor.
"It is expensive, education," he said. "But we've tried ignorance so many ways, and it doesn't work."