A long-denied feeling of victory and accomplishment settled over black communities in this city today as those who turned out in unprecedented numbers to elect Rep. Harold Washington (D-Ill.) the city's first black mayor began to savor the sweet taste of success.

There was joy, expectation and hope. There sometimes was a muted sense of racial pride and hard-earned respect.

There was a sense of finally being a part of the fabric of what many blacks today were thinking of as this grand old town. There was hero worship in such varied places as a welfare office on the impoverished west side and the shopping boulevards of middle-class south-side neighborhoods.

Many spoke of a new generation of young black voters, newly registered and determined to invest their energies in politics rather than ego and drugs. Some talked of the older generation, once apathetic but returning to the polls yesterday for the first time in decades and feeling good about it afterward.

Some offered sobering thoughts of how difficult it would be for Washington to become an effective mayor and longed for a healing of the wounds after a bitter and racially divisive campaign.

Though Washington's victory over Republican Bernard E. Epton was less than a day old, they already were compiling a broad and sometimes personal agenda for him--more jobs, less police brutality, racial harmony and a playground in a poor west side neighborhood overrun with idle teen-agers.

Yet first and foremost they were glad--glad that the election was finally over and that their candidate had won, glad that after years of frustration and doubt the diverse black communities of this city finally had reason to stick out their chests.

"It's such a great feeling to have. I was laughing all this morning. I just feel good," said Stella Blakely, 29, a dental hygienist from the south side, who said she couldn't count the number of times she had been told since moving from Mississippi a year ago that "we would never get a black mayor."

Roy Vincent, 72, a retired chemist, was ecstatic.

"I've been here since I was six. You know I'm happy," he said. "We've been hoping we would have someone who was a qualified person that could do the job, that had the knowledge."

"It was a dream come true," said south-side political activist Timuel D. Black. "It was something some of us had advocated and attempted and tried to put into play for at least 30 years."

Washington's victory was a political fairy tale of unity among the city's 1.2 million blacks. They had an astounding turnout of more than 80 percent and delivered more than nine of every 10 of their votes to Washington, a lawyer and 60-year-old minister's son from the south side.

"I can feel the movement, not just in Chicago, but all over the nation," said policeman and popcorn shop co-owner Karl Manuel. "Black people are finally coming together. This is going to really be something."

Of Washington, he added, "He'll end up being a national leader. He'll end up being a counterpart of Martin Luther King."

The victory was a crusade, weaned on years of frustration, ignited by incumbent Jane M. Byrne's repeated insensitivity, mobilized behind the candidacy of a flawed-but-charismatic man who symbolized generations of black leadership and galvanized by what many considered bald-faced racism.

In many respects, it was reminiscent of a major civil rights march of the 1960s, when black and white students went down South to help out and big-name entertainers and activists joined the line of march.

On one side of town, D.C. Mayor Marion Barry was passing out campaign literature, former Atlanta mayor Maynard Jackson was doing the same on another.

Bernard Demczuk, a Washington-based lobbyist for the American Federation of Government Employes, came in to work the white ethnic wards, where, he said, he was spat at and called "nigger lover" and saw the tires of fellow workers' cars slashed.

Yet most of the work was done by black Chicagoans, determined to shatter the notion that blacks, who long have been dependable Democratic voters--when they vote--could be taken for granted.

More than 150 telephones at a south side office were manned all day to help get out the vote, 1,800 students bused in from colleges were whisked about town to canvass door-to-door. Voter turnout was checked with a system developed by a group of black computer programmers. At one point, nearly 400 buses, taxicabs, cars and vans were shuttling voters to the polls. At some places on the south side, employers said they told their employes not to come to work without ballot stubs indicating they already have voted.

Hispanics, who had given 11 percent of their vote to Washington in the primary, increased that proportion nearly sevenfold. In some wards, Washington polled more than 99 percent among black voters.

One such was the 8th Ward, a middle-class section of the south side, where the ward boss, Cook County Commissioner John F. Stroger Jr., made Washington's election a matter of racial pride. Here nearly 86 percent of the 33,283 registered voters turned out and 31,174 chose Washington. Epton received 466 votes.

But today, many blacks were looking toward a healing of racial wounds, but certain that it would take a long time. And a few were looking for Washington and the reform movement he represents to tread carefully for fear of giving ammunition to those so anxious to say, 'I told you so.'"