His rented Impala paws the asphalt as the legendary investigative reporter takes a slow left off 47th Street and heads into the sunlight of Indiana Avenue.

Seymour Hersh has come home again, to the rough-cut precincts where he spent a good chunk of the 1950s working as a teenager in his father's dry cleaner.

In those days, Hersh says, he delivered pressed clothes to houses of prostitution, and his father accepted steaks from stockyard workers who couldn't come up with cash.

"This building didn't used to be here," Hersh says, peering through the Impala's sloped window at a sheet of fresh brick.

The 67-year-old executes a three-point turn against traffic and stabs a finger at a spot in an alley.

"That was home plate!"

From these streets sprang a groundbreaking journalist who has revealed some of America's darkest official secrets.

Hersh's 1969 disclosure of the My Lai massacre has been called pivotal in turning the tide of public opinion against the Vietnam War. He detailed President Nixon's secret bombing of Cambodia, CIA spying on American dissidents and the hidden nuclear arms programs of Israel and Pakistan.

Today, Hersh is widely credited with breaking the news that Iraqi war prisoners were abused at Abu Ghraib, although a few of the iconic photographs were aired on CBS' "60 Minutes II" on April 28, two days before his detailed account was posted by The New Yorker magazine. The scandal has roiled the Bush administration and refigured world opinion about the U.S.

"I can't think of a single reporter who has brought more important stories to light," said Bill Kovach, founding director of the Committee of Concerned Journalists and Hersh's editor at The New York Times during the 1970s.

"Sy exposed some of the most despicable behavior on the part of public officials," Kovach said. "He's made Americans aware when our leaders don't measure up to the values expressed in all the songs we sing and pledges we make."

Still charging at an age when many reporters are glad to grab desk jobs, Hersh returned this month to visit family and speak at the University of Chicago, where he graduated as a middling history major in 1958, met his wife of 40 years and flunked out of law school.

He is predictably skeptical of the accolades that have followed his Abu Ghraib revelations -- another crowning moment in a career that has seen jarring ups and downs. Along the way to winning a Pulitzer Prize and writing eight books, Hersh has been bashed by government officials, accused of misjudgment by peers and sued unsuccessfully for libel by wealthy, powerful men.

In 1975 when Donald Rumsfeld and Dick Cheney were top aides to President Gerald Ford, Rumsfeld floated a proposal to have the FBI search Hersh's home to halt his reporting on a submarine espionage program, papers from the Gerald R. Ford Library show.

Written in the face of libel threats and official denial, Hersh's New Yorker stories since the Sept. 11, 2001 terrorist attacks won a National Magazine last month. The New Yorker pieces helped expose the administration's false claim that Iraq got nuclear materials from Niger, broke news about the illicit nuclear weapons dealing of A.Q. Khan, the architect of Pakistan's atomic bomb, and traced sensitive NSA eavesdrops suggesting corruption among Saudi leaders.

His May New Yorker story "Chain of Command" alleged that Defense Secretay Rumsfeld personally authorized a secret program of harsh prisoner interrogation in Afghanistan that laid the foundation for the Abu Ghraib horrors. Pentagon spokesman Larry Di Rita called that story "outlandish, conspiratorial" and "journalistic malpractice."

But Di Rita did not raise specific factual challenges, telling the Tribune, "It's difficult to establish that anything in [Hersh's story] can be verified at all. He's referring to programs that don't appear to exist and meetings and conversations that don't appear to have taken place." Hersh has signed with HarperCollins Publishers to expand his New Yorker articles into a book scheduled for publication before the November election.

Hersh's New Yorker coverage "completely shifted the tone of journalistic discourse on the war," said Gretchen Soderlund, assistant director of the University of Chicago's Center for the Study of Communication and Society. "His pieces have probably served to remind a lot of journalists what journalism can be."

The most celebrated investigative reporters are often driven by a combustible mix of altruism and ambition -- a heartfelt desire to combat injustice and a sometimes unseemly need to wallop the competition and see their names in print. The limber 67-year-old who squints at the storefronts of 47th Street through oversize glasses brings all that and more to his work.