“George McGovern dedicated his life to serving the country he loved,” said Obama, in a statement released by the White House. 

“He signed up to fight in World War II, and became a decorated bomber pilot over the battlefields of Europe.  When the people of South Dakota sent him to Washington, this hero of war became a champion for peace. And after his career in Congress, he became a leading voice in the fight against hunger,” he added.

The president said he and the first lady’s “thoughts and prayers” were with the former senator’s family.

McGovern, who was his party’s presidential standard-bearer in 1972, died on Sunday at the age of 90. His family said he passed away at a hospice in Sioux Falls, S.D., where he had been admitted last week.

McGovern represented South Dakota’s first district in the U.S. House of Representatives from 1957 to 1961, and was a U.S. senator from 1963 to 1981, where he was a champion of his party's liberal wing. 

McGovern’s upstart campaign in 1972 captured the Democratic nomination, but he lost his bid in a crushing landslide to incumbent President Richard Nixon.

After his work in Congress, the Democratic icon focused his attention on fighting world hunger.

Vice President Biden on Sunday said he was “profoundly saddened” by the passing of a “generous, kind, honorable man.” 

“George believed deeply in public service. It defined him as a Senator and as a man. And he never stopped serving for his entire life,” Biden said.