A hundred years ago, any soapbox orator who called for women’s suffrage, laws protecting the environment, an end to lynching, workers’ right to form unions, a progressive income tax, a federal minimum wage, old-age insurance, the eight-hour workday and government-subsidized healthcare would be considered an impractical utopian dreamer or a dangerous socialist. Now we take these ideas for granted. The radical ideas of one generation are often the common sense of the next. When that happens, give credit to the activists and movements that fought to take those ideas from the margins to the mainstream. We all stand on the shoulders of earlier generations of radicals and reformers who challenged the status quo of their day.

Unfortunately, most Americans know little of this progressive history. It isn’t taught in most high schools. You can’t find it on the major television networks or even on the History Channel. Indeed, our history is under siege. In popular media, the most persistent interpreter of America’s radical past is Glenn Beck, who teaches viewers a wildly inaccurate history of unions, civil rights and the American left. Beck argues, for example, that the civil rights movement "has been perverted and distorted" by people claiming that Martin Luther King Jr. supported "redistribution of wealth." In fact, King did call for a "radical redistribution of economic power." Using his famous chalkboard, Beck draws connections between various people and organizations, and defines them as radicals, Marxists, socialists, revolutionaries, leftists, progressives or social justice activists—all of which leads inexorably to Barack Obama. Drawing on writings by conspiracy theorists and white supremacists, Beck presents a misleading version of America’s radical family tree.

Many historians, including Howard Zinn in his classic A People’s History of the United States and Eric Foner in The Story of American Freedom, have chronicled the story of America’s utopians, radicals and reformers. Every generation needs to retell this story, reinterpret it and use it to help shape the present and future. Unless Americans know this history, they’ll have little understanding of how far we’ve come, how we got here and how progress was made by a combination of grassroots movements and reformers.

Progressive change happens from the bottom up, as Zinn argued. But movements need leaders as well as rank-and-file activists. Movement leaders make strategic choices that help win victories. These choices involve mobilizing people, picking and framing issues, training new leaders, identifying opportunities, conducting research, recruiting allies, using the media, negotiating with opponents and deciding when to engage in protest and civil disobedience, lobbying, voting and other strategies.

This list includes fifty people—listed chronologically in terms of their early important accomplishments—who helped change America in a more progressive direction during the twentieth century by organizing movements, pushing for radical reforms and popularizing progressive ideas. They are not equally famous, but they are all leaders who spurred others to action. Most were not single-issue activists but were involved in broad crusades for economic and social justice, revealing the many connections among different movements across generations. Most were organizers and activists, but the list includes academics, lawyers and Supreme Court justices, artists and musicians who also played important roles in key movements.

The list includes people who spent most of their lives as activists for change—long-distance runners, not sprinters. Many of them were born in the nineteenth century but gained prominence in the twentieth. Some important activists who lived into the twentieth century but whose major achievements occurred in the previous century—such as labor organizer Mary Harris "Mother" Jones; environmentalist John Muir; African-American journalist, feminist and anti-lynching crusader Ida B. Wells; agrarian Populist leader Mary Lease; and Knights of Labor leader Terence Powderly—are not included.

Although many politicians were important allies of progressive movements—including Senator (and Governor) Robert La Follette; Senators Robert Wagner, Paul Douglas and Paul Wellstone; Congress members Victor Berger, Jeannette Rankin, Vito Marcantonio, Bella Abzug and Phil Burton; Mayors Tom Johnson, Fiorello LaGuardia and Harold Washington; as well as Presidents Franklin Roosevelt and (for his domestic social programs) Lyndon Johnson—the list excludes elected officials. (Eugene Debs, Harvey Milk and Tom Hayden, who were elected to public office, are included because they made their reputations primarily as activists.)

A few of the people on the list expressed views, at some point in their lives, that progressives consider objectionable, such as Margaret Sanger’s endorsement of eugenics, Earl Warren’s support for rounding up Japanese-Americans during World War II, Bayard Rustin’s support for the Vietnam War and Jackie Robinson’s attack on Paul Robeson. They made mistakes, which may be understandable in historical context, but which should be acknowledged as part of their lives and times.

There is, of course, much room for dispute about who belongs on the list—who is missing and who might be replaced. This listing is simply a starting point for further debate and discussion, which we invite you to join.

Editor’s Note: Check out a slide show of Peter Dreier’s lists —in chronological order, complete with photographs, links to articles from the Nation archive and suggested readings.

There is, of course, much room for dispute about who belongs on the list. We see this list simply as a starting point for debate and we’re asking readers to nominate names we missed, which we’ll prominently post as well.  With your help we also hope to begin a list of notable progressive of the twenty-first century. Submit your nominations here!