In this 28 Jan. 2008 file photo, then-Democratic presidential hopeful Sen. Obama smiles with Sen. Kennedy, during rally at American University in Washington
U.S. President Barack Obama says the United States has lost a "great leader" in Senator Edward Kennedy, who died Tuesday night at his Massachusetts home at the age of 77.
In a statement released early Wednesday morning by the White House, Mr. Obama said he and his wife, Michelle, are "heartbroken" about Kennedy's passing. The president paid tribute to the legendary lawmaker's work over nearly five decades in the U.S. Senate, on such issues as civil rights and health care.
Mr. Obama hailed Kennedy as "the greatest United States Senator of our time."
Kennedy's Senate colleague, Majority Leader Harry Reid, said it was "the thrill of my lifetime " to work with a man he called the "patriarch" of the Senate.
Republican Senator Orrin Hatch - one of Edward Kennedy's fiercest political opponents and closest friends in that chamber of the U.S. Congress - said the Democratic lawmaker will be remembered as "someone who lived and breathed the United States Senate, and the work completed within its chamber."
Nancy Reagan, the wife of the late President Ronald Reagan, called Kennedy "an ally and a dear friend." Despite the political differences between her husband, a hero of conservative Republicans, and the stalwart liberal Democrat, Mrs. Reagan said she and Senator Kennedy found common ground on the issue of stem-cell research.
Nancy Reagan has become a strong advocate of stem cell research, which many believe will lead to treatment for illnesses such as Alzheimer's disease, which led to President Reagan's death in 2004.
California Governor Arnold Schwarzenegger, who is married to Kennedy's niece, Maria Shriver, called him "the rock of our family," and a champion of social justice.
Ted Kennedy (1932-2009) 
United States Senator Ted Kennedy, a Democrat from Massachusetts died just before midnight on August 25, 2009, at his home in Hyannis Port at age 77. He was the brother of American President John F. Kennedy and  U.S. Senator Robert F. Kennedy.

On May 20, 2008, Kennedy was diagnosed with a brain tumor, and was released from Massachusetts General Hospital on May 21.

He was born Edward Moore Kennedy on February 22, 1932, in Boston. He had been a senator since 1962.

Kennedy is survived by his wife Victoria Reggie Kennedy, three children, two step-children, a sister — Jean Kennedy Smith, many nieces and nephews and several grandchildren.

The Kennedy family released a statement saying, "Edward M. Kennedy — the husband, father, grandfather, brother and uncle we loved so deeply — died late Tuesday night at home in Hyannis Port. We’ve lost the irreplaceable center of our family and joyous light in our lives, but the inspiration of his faith, optimism, and perseverance will live on in our hearts forever. We thank everyone who gave him care and support over this last year, and everyone who stood with him for so many years in his tireless march for progress toward justice, fairness and opportunity for all. He loved this country and devoted his life to serving it. He always believed that our best days were still ahead, but it’s hard to imagine any of them without him."

Kennedy was the second-most-senior current member of the Senate, after Democratic President ''pro tempore'' Robert Byrd of West Virginia, and the third-longest-serving senator of all time, behind Byrd and Republican Senator Strom Thurmond of South Carolina. Kennedy was known as "The Lion of the Senate," for his long tenure and influence in the Senate. Throughout his career, Kennedy and his staff wrote more then 300 bills that were enacted into law.

Because of Kennedy's death, the Democratic Party has lost their sixty-seat supermajority in the Senate. His successor will be chosen in a special election within 160 days. Prior to his death, Kennedy appealed to Democratic Massachusetts Governor Deval Patrick and the Massachusetts legislature to change state law regarding Senate vacancies, so that a temporary senator could be appointed pending a special election and a vote in favor of a health-care bill would not potentially be lost.  This law had been changed in 2004 to prevent Republican then-Governor Mitt Romney from appointing a replacement for Democratic Senator John Kerry, had he won the 2004 presidential election.