When Martin Luther King Jr. led the historic 1963 March on Washington, Walter E. Fauntroy was a minister and a leader in the Southern Christian Leadership Conference and Marion Barry and John Wilson were organizers for the Student Non-Violent Coordinating Committee.

Young, defiant and often militant, they labored outside the political establishment, demonstrating and organizing to achieve voting rights and economic power for blacks. They worked as well to regain home rule for the District of Columbia, a 70 percent black city that for years had been controlled by a small handful of powerful members of Congress.

Today the outsiders are the insiders, their names synonymous with the District of Columbia's political power elite: Fauntroy, the first elected D.C. delegate to Congress, is chairman of a House domestic monetary policy subcommittee that oversees the nation's economy. Barry, elected last fall to a second term as mayor of Washington, controls a $2 billion annual budget and a well-oiled city-wide political machine. And Wilson, the chairman of the City Council's Finance and Revenue Committee, has jurisdiction over all local tax legislation and is courted by the city's business community.

It is a phenomenon that has been repeated in hundreds of cities and towns throughout the South. Once the legal and political barriers came down, civil rights activists quickly moved from positions as street protesters to influential government officials.

"It was natural after we had fought and won the civil rights battle to move into traditional politics," says Fauntroy, a chief organizer of today's 20th anniversary march. "And those who did were those who had been tested as leaders in the movement."

In a sense, this was what the civil rights movement was all about, and the nation's capital stands as a conspicuous example of how much America has changed since that August day 20 years ago. Yet inevitably, the activists--and those who put their faith in them--were destined to be disillusioned, for they have discovered that it's just as hard or harder to effect change from inside government, in the face of perplexing budgetary problems or an intransigent bureaucracy, than it was out on the street.

Ronald Walters, a political science professor at Howard University, believes that the dominant role of former civil rights activists in local government may have raised unrealistic expectations among poor blacks.

"It was very heady stuff to wake up one morning and find that your mayor was black, and your city council was black or your school board was black," Walters says. "And that gave you the illusion of political power. And as a result of it, our politicians, I think, overpromised, and those individuals who followed them overexpected.

"I think now, what we're seeing is that once we begin to put electoral politics and politicians in their proper perspective, we'll find that we really do have to return to building strong community organizations," he says.

During the early 1960s, Washington was a magnet for bright young black activists who became caught up in the movement. Many of them, including Stokely Carmichael (now known as Kwame Toure), were students at Howard University.

A handful of groups, mostly SNCC, SCLC, the Urban League, the Black United Front, and the Congress on Racial Equality--whose leader, Julius Hobson Sr., was probably the pivotal figure in the movement here--set the tone of the civil rights debate in the once strictly segregated nation's capital.

The passage by Congress of the Voting Rights Act of 1965 was a watershed in the civil rights movement, opening the floodgates to mass voter registration of blacks throughout the South. Fauntroy and other D.C. activists helped mobilize blacks in South Carolina in 1972 in a successful move to unseat Rep. John McMillan, a staunch conservative and segregationist who reigned over the city for years as chairman of the House District of Columbia Committee.

McMillan's defeat was essential to getting home rule legislation through the House of Representatives the following year, according to Fauntroy.

That those who came out of the civil rights movement would have a powerful impact on local government was obvious in January 1975, when the members of the first City Council elected under the new Home Rule Charter were formally sworn in.

Sterling Tucker, former director of the Washington Urban League, a moderate group, became the council's first elected chairman. Most of the members of that first council, notably Hobson, Douglas Moore, Willie Hardy, Nadine P. Winter, Wilhelmina J. Rolark, David Clarke, Barry and Wilson, were community organizers or activists whose philosophies were forged by the civil rights movement.

"It was a very aware council, in terms of the community," recalls Tucker, who now runs a consulting firm. "People expected the council to run off and give away the country store. . . . In the early stages, some of the members were still damning the power structure and the system. I had to remind them that they were the power structure and system."

Four years later, with the inauguration of Barry, the accession of the movement veterans was complete. When the new mayor picked his advisers, many of them were from SNCC, including Deputy Mayor Ivanhoe Donaldson; Tina Smith, director of special services; Herbert O. Reid, a counsel to the mayor, and Courtland Cox, now involved in economic development.

"They had middle-class values, a middle-class view of the world, although everyone didn't necessarily have the possessions associated with middle-class living," says Cox of his fellow SNCC activists.

Charles Cobb Jr., a black journalist and former SNCC activist, explored the limits of what Barry and other SNCC alumni could do within government to combat poverty and urban blight in a television program that Cobb helped to produce in January for public television station WGBH-TV in Boston.

"Government, we've been told, can do little, even an especially sensitive government, like Mayor Barry's," Cobb said during the program called "In the Shadow of the Capitol." "So I keep asking myself why Marion, Ivanhoe and all my friends are in government. And why they haven't been more effective in helping the people who are at the center of their concerns. Part of the answer has to do with the nature of the governmental process. It's not designed for poor people. Part of the answer has to do with the way power changes people. Its seduction can narrow vision."

Asked during the program how being in government had changed him, Donaldson replied: "You know the SNCC people in government haven't switched roles. Many of them are still doing what they've always done, except they got a new form to do it in, and the taxpayers pay for it, you know, which is organizing for things that they think are important. Marion Barry, however, had really become the leader."

For his part, Barry said that he's now in position to do more to help a larger number of people than he ever could on the outside as a political activist. "So I'm in a position now, in my view, to make decisions that help a larger number of people with the least amount of effort."

But Douglas Moore, the stormy former City Council member and civil rights activist, contends that Barry and his top aides long ago compromised the ideals of the civil rights movement in order to wield political power and lead more comfortable, middle-class lives. One of the tragedies, Moore says, is that no one has come along since then to replace them as outside activists agitating for change.

"We have to get beyond the myth that having a civil rights leader as mayor makes a difference for poor people," says Moore. "There's no difference in what Marion Barry talks about and what Ronald Reagan talks about."

But Wilson doubts that Barry's philosophy has changed that much in 20 years.

"He might have changed what he wears, but not his philosophy," Wilson says. "It's just a different role he's playing now."

But then, perhaps betraying the ambivalence of his feelings, Wilson added that, "People have become more conservative. . . . It's not that their feelings have changed, but that there's no way in government to channel those feelings. . . . We got old. We got families and mortgages and we started to look at things a little different."