George McGovern, the former Democratic senator and presidential candidate, passed away on Sunday at the age of 90. McGovern’s decades-long career in Washington and his liberal politics etched his place in the history books and the minds of many Americans.

From his outspoken opposition to the Vietnam War to his 1972 presidential campaign and beyond, we look back at McGovern’s five most memorable career moments. (Did we miss any? The comments section awaits.)

(For a more complete look at McGovern’s life, check out The Washington Post’s Patricia Sullivan’s McGovern obituary, which touches on all of these moments.)

(Jim Mone/AP)

* 1965, takes on Vietnam War in speech: An opponent of the war in Vietnam, McGovern took to the Senate floor during his first year in the upper chamber in 1963 for a speech on disarmament, a portion of which was dedicated to challenging the war effort. Two years later, he attracted widespread attention for another anti-war speech. “We are further away from victory over the guerrilla forces in Vietnam today than we were a decade ago," McGovern said.

* 1968, major delegate and nomination reforms: McGovern spearheaded reforms as the head of a commission that led to changes in the way delegates were allocated in presidential primary campaigns. He helped pave the path for state primaries -- not party bosses -- to dictate delegate support.

* 1972, runs for president, defeated in landslide by Richard Nixon: After a late-starting campaign in 1968 that didn’t gain much traction, McGovern returned to the national stage four years later when he won his party’s nomination. (He made a 3 a.m. (!) floor speech at the Democratic convention, following a floor fight that year.)

In the general election, McGovern’s message met little success – he carried just Massachusetts and Washington, D.C. But he sounded an optimistic note on Election Night.

“There can be question at all that we have pushed this country in the direction of peace, and I think each one of us loves the title of peacemaker more than any office in the land,” McGovern said in his concession speech.

* 1972, the Eagleton vice presidential selection and “thousand percent” remark: McGovern’s selection of then-senator Thomas Eagleton as his running mate – reportedly done after considering him for less than an hour, would leave its mark on the campaign. Eagleton left the ticket as news of his hospitalization for mental health issues surfaced. McGovern had previously said he backed Eagleton “a thousand percent.”

* 2000/2001, wins Medal of Freedom, appointed United Nations global ambassador on hunger: Long after he left the Senate, McGovern was still leaving a mark on the issues he cared most about. In 2000, he was awarded the Presidential Medal of Freedom by President Bill Clinton, who called McGovern “not only a hero in war but a stalwart voice for peace in Vietnam. … For decades, his conviction never wavered, nor has his early commitment to bringing food to the hungry." Combating hunger was a central focus in McGovern’s career, and he was tapped to be the first U.N. global ambassador on hunger in 2001.