All four living former presidents were among the many mourners Wednesday who paid tribute to the life and legacy of the late Sen. Edward Kennedy.
During 47 years in the Senate, Kennedy worked with 10 presidents -- five from each political party. And despite his liberal streak, he didn't hesitate to cross party lines to achieve legislative goals.
His bipartisan efforts were reflected in the outpouring of sympathies from former Presidents Jimmy Carter, George H.W. Bush, George W. Bush and Bill Clinton, whose relationship with Kennedy was strained last year when the Massachusetts Democrat endorsed Barack Obama over Hillary Clinton.
But Kennedy's relationship with Carter was perhaps the most difficult one after Kennedy unsuccessfully challenged the incumbent Carter in the 1980 Democratic primaries. Some blame Kennedy's bid for Carter's loss to Ronald Reagan in the general election. But Carter didn't mention any of that in a written statement Wednesday.
"Sen. Kennedy was a passionate voice for the citizens of Massachusetts and an unwavering advocate for the millions of less fortunate in our country," Carter said.
"The courage and dignity he exhibited in his fight with cancer was surpassed only by his lifelong commitment and service to his country," he said.
The elder Bush said he and his wife, Barbara were "deeply saddened to learn Ted Kennedy lost his valiant battle with cancer."
"While we didn't see eye-to-eye on many political issues through the years, I always respected his steadfast public service -- so much so, in fact that I invited him to my library in 2003 to receive the Bush Award for Excellence in Public Service," he said in a written statement.
"Ted Kennedy was a seminal figure in the United States Senate -- a leader who answered the call to duty for some 47 years and whose death closes a remarkable chapter in that body's history."
The younger Bush spoke to Kennedy's wife, Vicki, to express his and his wife's "condolences, best wishes and prayers," an aide told FOX News. Bush said that "the senator was a great man who lived a full life."
In a written statement, Bush praised Kennedy for his passion and willingness to fight for his convictions.
"I was pleased to work with Senator Kennedy on legislation to raise standards in public schools, reform immigration, and ensure dignity and fair treatment for Americans suffering from mental illness," he said in the written statement.
"In a life filled with trials, Ted Kennedy never gave in to self-pity or despair," he continued. "He maintained his optimistic spirit, his sense of humor, and his faith in his fellow citizens. He loved his family and his country -- and he served them until the end. He will be deeply missed."
Former President Bill Clinton called Kennedy "one of the most influential leaders of our time" and "one of the greatest senators in American history" whose "big heart, sharp mind, and boundless energy were gifts he gave to make our democracy a more perfect union."
"As president, I was thankful for his fierce advocacy for universal health care and his leadership in providing health coverage to millions of children," he said in a written statement. "His tireless efforts have brought us to the threshold of real health care reform.
"I was also grateful for his efforts, often in partnership with Republicans as well as Democrats, to advance civil rights, promote religious freedom, make colleges more affordable, and give young Americans the opportunity to serve at home in AmeriCorps," Clinton added.