Washington ? Sen. Edward M. Kennedy said in a new book that he was not romantically involved with young Mary Jo Kopechne and that he never escaped the despair he felt after she died in the 1969 car crash that has been seared into the national consciousness as “Chappaquiddick.”

He acknowledged that he enjoyed women and drink but said reports of wild Kennedy excesses were exaggerated. He said he always has accepted the conclusion that a lone assassin killed his brother John and that Kennedy family members had worried about the emotional health of his brother Robert following John’s death in Dallas in 1963. He said it “veered close to being a tragedy within a tragedy.”

Yet it was the specter of Chappaquiddick that Edward Kennedy, the youngest brother, never could shake.

“That night on Chappaquiddick Island ended in a horrible tragedy that haunts me every day of my life,” Kennedy wrote in a memoir, “True Compass,” to be published posthumously on Sept. 14. The Massachusetts senator died last week at 77 following a yearlong battle with brain cancer.

Kennedy said his Catholic faith helped sustain him as he wrestled with guilt over the events of July 18, 1969, when he drove a car off a bridge into a pond on the tiny island. His own anguish, he said, paled in comparison with the suffering endured by Kopechne’s family.

“Atonement is a process that never ends,” he wrote.

The book offers an intimate look at the personal failings, tragedies and triumphs of the famed Kennedy family’s last surviving brother.

He recounted how his other assassinated brother, former Attorney General Robert F. Kennedy, asked then-President Lyndon Johnson to make him an envoy to try to broker a peace deal to end the Vietnam War. If Johnson had agreed, Edward Kennedy speculated, Robert Kennedy might have not have run for president in the 1968 campaign when he was shot to death.

Amid the regrets, Kennedy asserted his zest for what he considered to be the good life, but he mocked the exaggerated reports of his personal excesses.

“I have enjoyed the company of women,” he wrote. “I have enjoyed a stiff drink or two or three, and I’ve relished the smooth taste of a good wine. At times, I’ve enjoyed these pleasures too much. I’ve heard the tales about my exploits as a hell-raiser — some accurate, some with a wisp of truth to them and some so outrageous that I can’t imagine how anyone could really believe them.”

The memoir was obtained early by The New York Times and the New York Daily News.

In it, Kennedy said his actions on Chappaquiddick on July 18, 1969, were “inexcusable.” He said he was afraid and “made terrible decisions” and had to live with the guilt for more than four decades.

Kennedy drove off a bridge into a pond. He swam to safety, leaving Kopechne in the car.

Kopechne, 28, a former worker with Robert Kennedy’s campaign, was found dead in the submerged car’s back seat 10 hours later. Kennedy, then 37, pleaded guilty to leaving the scene of an accident and got a suspended sentence and probation.

He wrote that he had no romantic relationship with Kopechne, and he hardly knew her. He said they were both getting emotional about his brother’s death and decided to leave the party that was hosted by Robert Kennedy’s former staffers.

In the book, Kennedy wrote candidly about his battle with brain cancer and his “self-destructive drinking,” especially after the 1968 death of his brother Robert.

After his brothers’ assassinations, Kennedy said he was easily startled at loud sounds, and would hit the deck whenever a car backfired.