President Obama said today hailed Sargent Shriver as "one of the brightest lights of the greatest generation."
"Over the course of his long and distinguished career, Sarge came to embody the idea of public service," the president said in a statement. "His loss will be felt in all of the communities around the world that have been touched by Peace Corps volunteers over the past half century and all of the lives that have been made better by his efforts to address inequality and injustice here at home."
Serving in the Kennedy and Johnson administrations in the 1960s, Shriver ran the War on Poverty and founded or was an early advocate of groups, including Head Start, VISTA, Job Corps, Community Action, Legal Services, Upward Bound, Foster Grandparents and Special Olympics.
President Johnson dubbed him "Mister Poverty" for his work and accomplishments.
"He was a man of giant love, energy, enthusiasm, and commitment. He lived to make the world a more joyful, faithful, and compassionate place," the Shriver family said in a statement. "He worked on stages both large and small but in the end, he will be best known for his love of others."
He was the U.S. ambassador to France from 1968 to 1970. But Shriver's biggest foray into national politics came in 1972 when George McGovern chose him to replace Thomas Eagleton as his running mate on the ill-fated Democratic ticket.
Eagleton had pulled out of the race after revelations that he had been treated for depression and received electroshock therapy. Although McGovern declared that he would back Eagleton "1,000 percent," within a week he asked him to withdraw and picked Shriver, who was well-connected in Democratic politics as a Kennedy family member.
The McGovern-Shriver ticket lost to Richard Nixon and Spiro Agnew in the general election by 23 percentage points, one of the biggest landslides in U.S. presidential history.
Shriver married John F. Kennedy's sister, Eunice Kennedy, in 1953. The two started the Special Olympics, which became a worldwide movement. She died at age of 88 in 2009.
Diagnosed with Alzheimer's disease in 2003, Shriver motivated his daughter to get involved with a four-part HBO documentary, "The Alzheimer's Project."
Maria Shriver talked in 2009 to ABC News about the challenges of her father's disease.
"My kids dealt with the person that was sitting in front of them. Like, 'What are you doing, Grandpa?' And, 'What are you doing today?' And they didn't get into who my father was. They just got into who he was then. And I think that was a very valuable lesson to me," Shriver told "Good Morning America."
"Accept the person that's sitting in front of you. Stop trying to make them who they were. Let it go," she said.