She introduced a video, directed by acclaimed documentary filmmaker Ken Burns, featuring images of Kennedy sailing, conducting an orchestra, reading to schoolchildren, greeting American troops and endorsing Obama last January.
Fellow political leaders ranging from civil rights pioneer Rep. John Lewis to fellow Massachusetts Sen. John Kerry lauded Kennedy, with Lewis recalling his "moral obligation to do everything possible to make this world a better place."
Kennedy's presence was highly anticipated by longtime Democratic delegates.
Joe Reed, 69, has been to every Democratic convention since 1968 and can't remember every skirmish, debate or cocktail party.
But he says he will never forget Sen. Kennedy's legendary "The Dream Will Never Die" speech in 1980, an eloquent defense of liberal ideas that is still the defining anthem for the party's left wing.
"As he built up to a climax, the crowd roared and took him and accepted him with all its heart," remembers Reed, the first black delegate from Alabama. "People were shouting and hollering -- that one will always stick out for me."
Reed, who is attending this week's convention in Denver, says he will be thinking of that speech and the Kennedy legacy when he gathers with his fellow delegates to nominate Barack Obama as their candidate.
"Kennedy's going to get the crowd stirred up," says delegate Eufaula Frazier, 83, a Miami civil rights activist who has been a regular at the party's conventions since 1972.
"He is one of the veterans of the civil rights movement and the progressive era, and Obama is the rookie who is picking it up and carrying it into the 21st century. There is so much history in this."
Kennedy's cancer struggle and his family's legacy are sure to make his appearance one of the highlights of the convention, especially in light of his dramatic endorsement of Obama in January that was considered one of the defining moments of the hard-fought Democratic primary.
"It will rally the troops," says Ted Sorensen, a speechwriter for Kennedy's brother, President John F. Kennedy, who is scheduled to give his own speech at the convention Tuesday.
"He is the lion of the Senate and the leader of the party's progressive forces," Sorensen says. "A shock and a shudder ran through the party when he was first hospitalized with the brain tumor, but this video appearance shows that he's not going away."
In addition to the 1980 speech, Sorensen said he remembers Kennedy's speech at his assassinated brother's Robert Kennedy's funeral in 1968 and at the Council on Foreign Relations to protest the Iraq War in 2004.
"He speaks clearly and powerfully, he's very natural on the platform, using many poetic allusions," Sorensen says.
Former New Jersey Gov. Brendan Byrne says he still recalls the threat that Kennedy posed to Carter's candidacy in 1980. "There is a magic about Ted partly because of our devotion to Jack, but he has a charm of his own.