Born in Boston on February 22, 1932, Edward Moore Kennedy was the last of nine children of Joseph P Kennedy, a prominent businessman and Democrat, and Rose Fitzgerald Kennedy.
Nicknamed 'Ted,' he was the younger brother of slain President John F Kennedy and New York Senator Robert Kennedy.
Kennedy, who was known as the 'Lion of the Senate,' played major roles in passage of the Civil Rights Act of 1964, the Voting Rights Act of 1965, the 1990 Americans with Disabilities Act and the 1993 Family and Medical Leave Act.
Kennedy suffered a seizure in May 2008 at his home on Cape Cod. Shortly after, doctors diagnosed a brain tumor-a malignant glioma in his left parietal lobe.
However, he insisted on making a brief but dramatic appearance at the 2008 Democratic convention, a poignant moment that brought the crowd to its feet and tears to many eyes.
"I have come here tonight to stand with you to change America, to restore its future, to rise to our best ideals and to elect Barack Obama president of the United States," Kennedy told fellow Democrats in a strong voice.
Kennedy was one of only six senators in US history to serve more than 40 years.
Kennedy championed social causes and was the author of 'In Critical Condition: The Crisis in America's Health Care.' He served as chairman of the Judiciary and Health, Education, Labor, and Pensions committees and was the ranking Democrat on the Judiciary and Armed Services committees.
Obama named Kennedy as one of 16 recipients of the 2009 Presidential Medal of Freedom, America's highest civilian honor.
Kennedy is survived by his second wife, Victoria Ann Reggie Kennedy,his first wife, Joan Bennett; and five children-Patrick, Kara and Edward Jr. from his first marriage, and Curran and Caroline Raclin from his second.