Washington — It was a success in numbers, with the estimated 250,000 marchers surpassing the figures for 1963. But many said that Saturday's march on Washington to commemorate the rally of 20 years ago came up short in some respects: It was not as successful at inspiring blacks to action, and failed to give blacks a specific agenda for the next two decades.
The difference between 1983 and 1963 involves the economic discrimination of today vs. the overt racial discrimination of 20 years ago, says Mayor Andrew Young of Atlanta, a planner in both demonstrations.
''Economics is the wave of the future for civil rights,'' he said in an interview after the rally. ''We must find a way to desegregate corporations - at the board level, through franchises, and through dealing with black businesses.
''In 1963, people shared common experiences - jail, water hoses, dogs, mean police. . . . In Washington, they received the message, then fought and won voting rights, public accommodations, and school desegregation after the march.''
Saturday's march, however, brought about one specific action: the planning for a new permanent organization called the Coalition of Conscience.
The group will offer ideas that were brought to the march on Washington Saturday. This coalition will replace the Rainbow Coalition, born after the original march on Washington in 1963, inspired by the ''I have a dream'' address of Dr. Martin Luther King Jr.
The new effort faces these challenges:
* Many blacks disapprove of the nostalgic emotionalism displayed by the crowd that blanketed the Mall between the Lincoln and Washington monuments. Marchers braving the intense summer heat chanted, ''We shall overcome.'' They held hands, singing and extolling Dr. King.
Critics of the march say they want to see evidence of strong black leadership and achievement of Dr. King's ''unfulfilled dream.'' They hope to see leaders emerge from black churches and organizations, and civil rights groups. They also seek support from white groups sympathetic to their cause.
* Other groups favor certain specific actions. They want to oust President Reagan in 1984; pass effective fair-housing legislation; get Senate approval of the House-passed bill making Dr. King's birthday a national holiday; and pass and implement a proposed full-employment bill. These goals are considered short-range by critics.
* Still others want to encourage the expansion of black interest in such areas as the environment, disarmament, and foreign policy. This would broaden the reach of the black movement beyond the aims of the Coalition of Conscience. The coalition itself plans to embrace a wide constituency, including Hispanics, white women, and American Indians.
Among the estimated 250,000 people who attended, there was a feeling of pride in surpassing the 200,000 that came in 1963, but there was also disappointment that no new Martin Luther King Jr. appeared on the horizon. The speaker that most stirred the crowd was The Rev. Jesse L. Jackson.
Mr. Jackson opened by having the crowd repeat with him several times, ''I am somebody.'' He did not, however, use the occasion to announce his candidacy for president.
Asked after the march about his intentions, Mr. Jackson said in a brief interview: ''I haven't really decided. I have to look at organization, support - and of course, money - to determine whether I can make a real run.'' He did not say when he will make his decision. Staff correspondent Peter Grier reports:
It was hot, though not as hot as Washington in August can be. A black woman had spread a newspaper over her head, against the sun. ''You sit here long enough,'' she said, ''you see some strangem stuff.''
A contingent from the Consumer Party '84 marched by, carrying red banners that said, ''Dennis Serrette for President.'' They were followed by the USA Green Party, and by a group whose signs proclaimed they were ''Quakers for Gay Civil Rights.''
To be sure, many of the marchers were from more traditional interest groups, such as the Communications Workers of America (who towed a small blimp that said , ''We remember the dream.''), the United Methodist Church, and the National Association for the Advancement of Colored People (NAACP). But the diverse nature of the crowd echoed the question march leaders had been asked all week: Wasn't this demonstration, despite its size, much less united than its predecessor in 1963?
There was, of course, the unifying symbol of Martin Luther King Jr. His visage was everywhere: on T-shirts, on posters, on the backs of paddle fans. ''I believe King's vision was America's vision, and yours and mine,'' said the woman running the ''Pies for Peace'' booth. ''Sorry, I'm out of pie.''
But the demonstrators, after they settled in their seats, proved to have at least one other strong tie - a dislike of Ronald Reagan. The crowd, which included many whites, applauded most when Reagan was attacked in speeches.
''Our national leaders must be retired,'' said District of Columbia Mayor Marion Berry. The crowd cheered. ''We are here because we are committed to eliminating Reaganism from the face of the earth,'' said NAACP head Benjamin L. Hooks. The crowd cheered louder.
As the afternoon and the speakers droned on, the gathering took on the air of a mass picnic, instead of a demonstration. Then The Rev. Jesse L. Jackson shattered the torpor. His subject was also politics, instead of vague ideals; specifically, voter registration. ''Register and rise!'' he yelled.
The crowd was roused to a religious call and response. (''Tell it!'' they said. ''Bring it down, Jesse!'') There was of ''Run, Jesse, run!'' But Mr. Jackson said nothing about a presidential candidacy.
If the demonstration had a theme, it may have been the message on an sign left crumpled on a rubbish pile: ''The age of rights is over. The struggle now is for power.''