POTOMAC, Md. – R. Sargent Shriver was always an optimist, pioneering the Peace Corps and running the War on Poverty during the turbulent 1960s — an idealist even as the running mate on a Democratic presidential ticket doomed for failure.

At his funeral Mass on Saturday, mourners from philanthropist and musician Bono to Vice President Joe Biden to former President Bill Clinton honored a man who dedicated his life to serving others. The celebration was filled with songs, laughter and fond memories.

“Fifty years ago, President Kennedy told us we should ask what we can do for our country,” Clinton said. “A whole generation of us understood what President Kennedy meant by looking at Sargent Shriver’s life.”

“I was a student really of the Sarge way of doing things,” U2 frontman Bono said after singing at the service. Bono founded the Red Campaign with Shriver’s eldest son Bobby to fight AIDS in Africa.

“It’s a rare combination of grace and strategy,” Bono said of Sargent Shriver.

First lady Michelle Obama and Oprah Winfrey attended. Wyclef Jean and Vanessa Williams sang, as did Glen Hansard, who starred in the movie “Once.”