Gravels child, Lynne Mosier, verified his death to CNN in a text on Sunday, remembering her father as a “excellent papa.”Born May 13, 1930, in Springfield, Massachusetts, Gravel served in the United States Army as an adjutant in the Communications Intelligence Service in Germany and an unique representative in the Counter Intelligence Corps in France from 1951 to 1954, according to a biography on his website. After his time in the military, Gravel finished from Columbia University in 1956 with a Bachelor of Science degree in economics. He served in the Alaska House of Representatives from 1963 to 1966 where he was chosen state House Speaker in 1965. Gravel was chosen to Congress in 1968, where he acted as a senator from 1969 to 1981. In 1971, Gravel acquired across the country attention after he checked out parts of the Pentagon Papers, a collection of dripped top-secret details about the Vietnam War, into the Congressional Record in an effort to end the war. The files showed that senior leaders, consisting of several presidents, believed the war was unwinnable, and that the federal government had misinformed Congress and the public about its development. He introduced an unsuccessful quote for the presidency as a Democrat in 2006, and later on, after ending his project, revealed he would change to the libertarian celebration. After a stopped working long-shot campaign for the presidency in 2019, he backed Vermont Sen. Bernie Sanders.The Gravel Institute, a progressive think tank established by the previous senator, also confirmed his death and remembered him in a tweet Sunday.”We are sad to reveal that Senator Mike Gravel died in harmony, surrounded by family, at his house in Seaside, California. He was 91, and had lived the fullest live (sic) anyone could have ever wanted. We will miss him every day,” the institute said.Gravel was likewise creator and chairman of the not-for-profit Democracy Foundation.CNNs Nicky Robertson added to this report.