BOSTON — Sen. Edward M. Kennedy began his final journey yesterday, first past landmark after landmark bearing his family's famous name and then to his slain brother's presidential library where mourners lined up by the thousands to bid farewell to him and an American political dynasty.

Crowds assembled along the 70-mile route that snaked from the family's compound in Hyannis Port to the John F. Kennedy Library and Museum, where his body lay in repose. As many as 12,000 people waited in line to file past his closed casket and mark the end of a national political chapter that was equal parts triumph and tragedy.

Kennedy's widow, Vicki, who greeted well-wishers filing past the casket, said the outpouring was deeply moving for the family.

"I just want to thank them so much for coming this evening and showing love and support for my husband," she said. "It's a tremendous solace to all our family."

The motorcade started in Hyannis Port, at the Cape Cod home where Kennedy's family held a private Mass. Eighty-five relatives traveled in the motorcade. They passed several sites that were significant to the senator, including St. Stephen's Church, where his mother, Rose, was baptized and her funeral Mass celebrated, and a Boston park he helped create that was named for his mother.

The procession also passed the Massachusetts Statehouse — with its life-size statue of John F. Kennedy — and a nearby building where Kennedy opened his first office as an assistant district attorney and where John Kennedy lived while running for Congress in 1946.

Kennedy died at age 77 Tuesday night after a brutal battle with brain cancer.

An invitation-only celebration of his life tonight is expected to be attended by dozens of members of Congress.