At 17, Warner Coleman has carved his niche in history. On Saturday, the District resident was the youngest speaker at the 20th anniversary March on Washington.

Coleman, a senior at Calvin Coolidge High School, spoke briefly under a section of the program called "Litany of Commitments to Jobs, Peace and Freedom."

Although that undoubtedly was his most widely known activity to date, the lanky teen-ager is no novice to demonstrations or to politics. He is the citywide youth representative to D.C. Del. Walter Fauntroy and serves as special assistant for youth affairs to council member Charlene Drew Jarvis (D-Ward 4).

A self-motivator, Coleman has been volunteering for causes and campaigns since he was 14 years old and has made friends with some famous people, including musical celebrity Stevie Wonder.

"Anything I feel is worthwhile. . . . I feel it's my responsibility as a youth to help," said Coleman, who also spoke in 1981 at a mass rally against U.S. involvement in El Salvador. "I've looked at how things go on with youths hanging in the streets and I don't want to be like that."

"He knows no bounds to his interest," Jarvis said. "He doesn't say, 'This is something I can't do.' . . . He just came into my campaign office one day in 1979 and said his name was Warner Coleman and that he was there to do anything he could do. When he told us he was going to be the youth speaker at the march, we weren't surprised."

Coleman's mother Delores, a laboratory technician at the National Institutes of Health in Bethesda, said her son's determination and sense of responsibility come from her encouragement and from his experiences on her parents' farm in Caroline County, Va.

Coleman lives with his mother and two sisters, aged 4 and 12, in an apartment in a middle-class neighborhood on Marietta Place NW.

"Warner has visited my father's farm most summers since he was 6," his mother said. "He learned that everyone there learns to do all of the jobs and not just one job."

"I've told him if he's going to do something, to associate with people who could help him," added Delores Coleman, who encouraged her son's first election campaign--for president of the Paul Junior High student council--when he was in the ninth grade. He won.

Coleman, whose friends jokingly call him "Mister Congressman" or "mayor," said he is not sure what moves him to get involved in so many issues.

"In 1980, I heard on the radio that Stevie Wonder was planning a march around Martin Luther King's birthday," he said. "I volunteered and spent time answering the phones, mailing letters and running errands."

Coleman returned to help with the King birthday marches of 1981 and 1982. This year, when Wonder held a news conference instead of a demonstration, Coleman joined him in singing a composition by the musician, a tribute to King. At a reception after Saturday's march, Coleman sat next to Coretta Scott King and talked with her about her husband.

Although someone in the national coalition that planned the march wrote the youth's speech, Coleman said the script had his approval.

"The young people of my generation have inherited the dream of Doctor Martin Luther King Junior," it began. "We now have a serious responsibility to join in the struggle for jobs, peace and freedom."

"I was fired up by the time I reached the words 'Before we were born, many people dreamed with Martin Luther King Junior that one day their children would be free at last, free at last,' " he said.

After working at the national march headquarters until 2 a.m., the youth said, he had only an hour's sleep, then had to return by 4:45 a.m. Saturday for a briefing.

He learned recently that his name is in the next edition of "Who's Who Among American High School Students." He hopes to attend Howard University, do graduate work in communications at Columbia University and get a job in broadcasting.