I stood amid a forest of scientists. It was still early on Saturday morning. Crowds of protesters gathered in large clumps on the lawn surrounding the Washington Monument. The mood was mellow, eased by the upbeat jazz music blasting from loudspeakers. But dark clouds were gathering above us. What I hoped would remain a light drizzle had transitioned into a persistent patter. Ill-prepared protesters held their soaked signs. Drenched myself, I sought protection in a tree grove. Many others flocked there as well. A pocket of white-coated scientists stood between the trees. A silent, giant Beaker the Muppet passed by me, as I watched an astronaut talking to Ms. Frizzle—the science teacher from “The Magic School Bus” TV series. Even the trees told me their political opinions; signs hanging from the branches warned me about the dangers of “alternative facts.” As I wandered among the trees, I felt like Alice in Scienceland.

Many of my fellow graduate students at Princeton University and I feel like we’ve been thrown into a topsy-turvy world. We have struggled to process our feelings about the political climate. Last November’s election galvanized some of my friends to become involved in local politics. Students who would have never considered themselves political started to volunteer at rallies and to call their congressional representatives. A group called the Princeton Citizen Scientists successfully organized a day of teach-ins for students, professors, and community members. A few members of the group joined me in Washington during the March for Science.

As I listened to the speakers on the main stage, I wondered about the relationship between scientists and public protests. I am professionally and personally interested in this subject because I study the history of science communication in the 20th century. A few months ago, I decided that I wanted to learn more about the history of scientific activism. Two books have proved particularly helpful to me: Peter J. Kuznick’s Beyond the Laboratory: Scientists as Political Activists in 1930s America and Alice Kimball Smith’s A Peril and A Hope: The Scientists’ Movement in America 1945–47. Both have made me think about how people of the future might view the scientist-activists of 2017.

The original teach-in. Kuznick’s narrative describes the first American science teach-in, which took place on the 130th anniversary of President Abraham Lincoln’s birth: February 12, 1939. Organized as a protest against the rise of fascism in Europe, the day of lectures promoted the importance of democracy, tolerance, and science—at 26 meetings around the country. Younger graduate students and adjuncts rose to the task and educated the public about how democracies protect scientific values.

Franz Boas, an anthropologist at Columbia University, was responsible for organizing and rallying young scientists. He proclaimed, “Never before have such a large number of scientists taken part in simultaneous meetings focusing attention on the fact that intellectual freedom is imperative in a democracy.” Additionally, during the teach-ins, scientists addressed ways to combat racial, religious, and ethnic discrimination. At the time, the public attendance exceeded the expectations of those involved. Although it wasn’t replicated again, this day of public lectures was hailed as a success.

Post-World War II protests. The young graduate students who attended these meetings later became involved in activism after World War II, protesting nuclear weapons and McCarthyism. These students are the subjects of Kimball Smith’s book.

Immediately after World War II, American physicists set to work trying to educate the public. They published books about physics, wrote pamphlets, and gave lectures. Physicists even collaborated with filmmakers on a 1945 movie about the history of nuclear weapons.

In 1962, Nobel laureate Linus Pauling marched along the same Washington streets where I stood on Saturday. American women marched alongside him, members of the organization Women Strike for Peace, rallying against the proliferation of nuclear weapons. In a famous photograph from that rally, Pauling stood in front of a dozen women, holding a sign above his head. “Mr. Kennedy, Mr. MacMillan,” it read (addressing the US president and British prime minister at that time), “We have no right to test.” Scientific activists were at least somewhat successful in their aims; the Partial Test Ban Treaty, prohibiting signatories from conducting aboveground test detonations, was signed in 1963.

A massive meetup. As I walked amid the crowds at the March for Science, I thought about these previous scientific movements. A few of the protesters that I chatted up had protested the Vietnam War in the 1970s. One smartly dressed German couple enthusiastically remembered that they had successfully agitated against nuclear proliferation in Bonn. They might have been young children in the 1960s during the anti-nuclear proliferation protests. Largely, I saw Saturday’s protest as a physical expression of the public’s love of science. The satellite marches that happened across the country (and around the globe) provided scientists and non-scientists alike with an opportunity to publicly come together.

One of my favorite signs read: “Help Others Care: Vocalize Your Research.” The best moments of the march occurred when scientists did just this: They took a few moments to explain to non-scientists how their research affects everyone. Talking with a few marchers, I learned about current trials for breast cancer research, new research being done with radio telescopes, and new developments involving fusion reactors. The march also provided an occasion for scientists to meet across disciplinary lines and affirm their common values. Protesters’ signs, many with pithy slogans and jokes, provided an opportunity to strike up conversations and to express solidarity.

The march’s legacy. A few protesters were pessimistic. They worried that the march had been poorly organized. What would the participants really take away from it? Did they actually learn something about science? The dark storm clouds above us matched their mood. Like scientists before them, they worried that the public would quickly return to a state of apathy. Could quirky signs and costumed characters really make much of a difference?

I tried to stay optimistic. Notably, many of the protesters were children. They clutched homemade posters with drawings of polar bears and planets that ran with the rain. Some wore hats imprinted with DNA molecules. Others sat in the trees above my head, holding their signs and watching the crowd.

As a historian, I think a lot about how current events will be remembered. Perhaps little will change in day-to-day public policy. On the other hand, Saturday’s march might inspire young activists. I’m guessing that some of the young children who attended Saturday’s protests will become scientists. Maybe their soggy signs will help them connect to each other. The March for Science could be a cultural touchstone for them. One day, they might be inspired to organize their own teach-ins. These kids might have been wet and cold on Saturday. Nevertheless, like generations of activists before them, they will persist.