“Demonstrations don’t work.” Next time you hear someone (or yourself) say that, you might consider the Moratorium and Mobilization demonstrations in the fall of 1969 — both commemorating their 50th anniversaries this year.

On Oct.15, 1969, more than two million citizens took part in the Moratorium — a one-day national strike against the war. In hundreds of cities, towns and campuses throughout the country, people from all walks of life took the day off to march, rally, vigil or engage in teach-ins. Until the Women’s March of 2017, the Moratorium held the title as the biggest nationwide demonstration in American history.

Exactly a month later, on Nov. 15, more than a half-million war opponents flooded the nation’s capital for the Mobilization. That was more than double the number of marchers who participated in the famous 1963 March on Washington led by Martin Luther King, Jr. More than 100,000 rallied in a simultaneous antiwar demonstration in San Francisco.

It’s not just the enormous size of these antiwar protests that make them worth recalling. I was on the staff of the coalition that organized the Mobilization action. Though none of us involved knew it then, these demonstrations foiled Richard Nixon’s plans to dramatically escalate the war.

At the time, I was delighted with the massive turnouts. I’d been working full-time as an antiwar organizer for the previous two years and would continue doing so for four more. I believed the antiwar movement was making progress as more and more people from an ever-broadening cross-section of the public were joining the actions. It seemed the tide of public opinion was shifting in our favor.

But was the dissent having any impact on the warmakers? After all, the war was continuing to send both Americans and Vietnamese to early graves every day. I sometimes wondered whether the peace movement was no more than a side show. The government always pooh-poohed our influence. Nixon even claimed to have watched a football game while a half-million of us marched and rallied within earshot of the White House.

Few could have predicted earlier in the year that the peace movement would have launched such massive protests. When Nixon entered the Oval Office in January, the national peace movement was in disarray. It’s well worth telling the story of how the movement transformed itself over the ensuing months. It certainly illustrates why it’s so crucial for mass protests to be creatively nonviolent.

Fewer than 10,000 people showed up for “Counter-Inaugural” actions, which were held in Washington, D.C. when Nixon took office. It was sponsored by the Mobilization coalition that had called other national demonstrations. (The two coalition protests in 1967 each drew more than 10 times that number). And the Counter-Inaugurals were widely considered a flop. The most publicized actions were minor street skirmishes between the police and small bands of protesters, some of whom threw objects at Nixon’s car as it made its way down Pennsylvania Avenue to the White House.

Even before the Counter-Inaugurals, the Mobilization’s leadership had little credibility. Opponents of the war were wary of a repeat of the violence that occurred the previous summer at the Chicago Democratic Convention. The Chicago demonstrations had also failed to attract more than 10,000 in part because of the violent rhetoric and provocative statements made by Mobilization leaders. At one point, Tom Hayden exhorted a crowd: “Make sure that if blood is going to flow, let it flow all over the city.”

Most antiwarriors understood that Mayor Richard Daly and the Chicago police were responsible for the violence, not the protesters. (A government commission called it a “police riot.”) Still, it’s hard to recruit large numbers of people to an event where you think you might get your head bashed in. And the Mobilization leadership had done little either in Chicago or at the Counter-Inaugural to dissuade those within the antiwar movement who spouted violent rhetoric (“Off the pig” was a favorite chant) or advocated violent tactics.

During the first months of the new administration, some antiwarriors were willing to give the new president the benefit of the doubt to see whether he would become the “peacemaker” he so eloquently proclaimed in his inaugural address. Believing in his powers of persuasion, Nixon’s aide Henry Kissinger met with a group from the major antiwar religious coalition to urge patience. His effort backfired. Two weeks later, the group announced a series of demonstrations in the spring, as did other antiwar groups who had concluded that Nixon — like his predecessor, Lyndon Johnson — hoped to win a military victory despite his talk of turning responsibility for the war over to the South Vietnamese, as well as enacting token troop withdrawals.

Kissinger had the same luck several weeks later with a group of student leaders. They represented more than 250 student body presidents and college newspaper editors who had signed a petition saying they would refuse to be drafted into the military. Meeting in the Situation Room in the basement of the White House, Kissinger gave his spiel about patience. It did not go over well with students who faced being drafted and possibly being sent to prison or Vietnam while Nixon and Kissinger were patiently trying to achieve “peace with honor.” After Kissinger left the room, John Ehrlichman, Nixon’s senior aide, told the group, “If you people think you can break laws just because you don’t like them, you’re going to force us to up the ante to the point we’re handing out death sentences for traffic violations.” He slammed his hand on the table and the meeting was over.

Leaders of the student group soon organized the Vietnam Moratorium Committee and called for people to stop work or school on Oct. 15 to protest the war. They intentionally picked the word “moratorium” rather than “general strike” to appeal to a broad cross-section of the public, especially those who’d never previously taken to the streets. Leaders of the Moratorium saw the potential for enlarging the movement after having worked on the 1968 electoral campaign of antiwar candidate Eugene McCarthy. They urged people to protest in their own communities with the Moratorium functioning as a clearinghouse to support local groups.

Meanwhile, a newly formed coalition emerged with a wide spectrum of community, religious, professional, labor, political and student groups. Called the New Mobilization Committee to End the War in Vietnam, its organizers went to great lengths to eliminate the violent rhetoric and confrontational street tactics that had marred previous coalition actions.

The Mobilization called for major rallies in Washington, D.C., and San Francisco for Nov. 15. To set a peaceful tone, they added a solemn two-day March Against Death immediately prior to the mass rally in Washington. The plan was to march from Arlington Cemetery to the Capitol via the White House with marchers holding placards with the name of a U.S. soldier who’d been killed in the war or the name of a Vietnamese village that had been destroyed.

Earlier that spring, some local groups had adopted the tactic of reading the names of the war dead in front of government buildings. The tactic served to remind the public that the war was not over, that the killing was continuing. The tactic got national network coverage when a group of Quakers did it on the steps of the capitol and were joined by a handful of Congresspeople. Because it was then illegal to demonstrate on the Capitol grounds, the demonstrators were hauled off to jail, but the representatives could not be arrested because of congressional immunity. (The Quakers successfully challenged their arrests, and a judge found in their favor — making it legal to exercise one’s First Amendment rights at the Capitol.)

While antiwarriors were making plans for the fall, Nixon had initiated what he called his “Madman Theory,” which involved threatening the other side with massive destruction if they didn’t agree to his peace terms. The president gave the communists a deadline of Nov. 1 to agree to the American peace terms or face “measures of great consequence and force” and had his aides imply that the fervently anti-Communist president could be unpredictable or even act irrationally if angry.

Nixon then had the Pentagon and his National Security Council led by Kissinger draw up plans to deliver a “savage, decisive blow” against North Vietnam because, in Kissinger’s words, “I refuse to believe that a little fourth-rate power like North Vietnam doesn’t have a breaking point.” Plans included bombing the country’s dikes — which could have killed tens of thousands of civilians — as well as dropping so-called tactical nuclear bombs near the Chinese border, which could have provoked the nuclear-armed Chinese or Soviets to retaliate.

Unfortunately for Nixon, his ultimatum date of Nov. 1 was sandwiched between the dates for two antiwar demonstrations. When Nixon learned from CIA infiltrators that the Moratorium was “shaping up to be the most widely-supported public action in American history,” he saw trouble ahead. As Nixon later wrote, he saw that “the only chance for my ultimatum to succeed was to convince the Communists that I could depend on solid support at home if they decided to call my bluff.”

“Solid support at home” was not forthcoming. The size and breadth of both the October and November protests surpassed the organizers’ most grandiose expectations. Reading the names of the war dead was used extensively during the Moratorium protests. And the March Against Death drew more than 45,000 protesters who walked single file along the four-mile route with their candles and placards for 36 hours.

The Mobilization also attempted to create a highly disciplined action by recruiting and training more than 4,000 marshals to keep order. Their one-and-a-half hour nonviolent training sessions included several role-playing scenarios about how to deal with potential disrupters, whether police, agents provocateurs or radical activists. (The latter was a major concern, as Bill Ayers of the newly formed Weatherman faction tried to extort $20,000 from demonstration leaders in exchange for agreeing not to disrupt the action. He was turned down.)

As a result of the demonstrations, Nixon cancelled his war plans. He wrote in his memoirs that the protests had “undercut the credibility of the ultimatum.” Several other researchers have verified that in this instance at least, “Tricky Dick” (as he was then called), had told the truth.

What about Nixon’s claim to have ignored the Nov. 15 Mobilization? “Untrue,” according to Daniel Ellsberg, who was then working for the Nixon administration: “Every 10 minutes he [Nixon] was calling the Situation Room and finding out what was going on, getting the reports from the U-2s on crowd size… He was totally absorbed.”

Of course, the fall 1969 demonstrations did not end the war. It was one battle in a 10-year nonviolent struggle that ultimately helped to stop the bloodshed in Indochina. Admiral Thomas Moorer, chairman of the Joint Chiefs of Staff during the Nixon administration, acknowledged that the government always was concerned about how the antiwar movement would react. He said that the movement “served to inhibit and restrain the decision makers… both in the executive and legislative branches of the government.”

It’s worth reflecting on the implication of Admiral Moorer’s statement. To “inhibit and restrain” warmakers in wartime meant less violence. Put another way, the anti-Vietnam War movement saved lives.

Sadly, few of us who were involved in American’s largest nonviolent struggle knew then or know today that we had such power. At the time, we knew opposing the Vietnam War was the right thing to do. But it sure helps to realize that it made a real difference to have marched and rallied, petitioned and lobbied, sat through countless meetings and engaged in civil disobedience.

Hopefully, those involved in today’s struggles will find some helpful lessons from our experiences.