More than 200 social-policy administrators and experts began a nostalgia-filled conference yesterday designed to celebrate the legacy that began 21 years ago when the first federal Community Action Grants initiated the "War on Poverty."

In attendance at the conference, sponsored by the National Neighborhood Coalition, were administrators of federal social programs during the Johnson, Nixon, Carter and Reagan administrations.

They included Frank Carlucci, former director of the Office of Economic Opportunity (OEO) under President Richard M. Nixon; William Allison, deputy OEO director under President Jimmy Carter; Jerrold Speers, currently its acting director, and Hyman Bookbinder, executive officer of the president's task force on poverty in 1964 and assistant OEO director under President Lyndon B. Johnson.

"I have become weary, even angry at times, of writers and politicians who reject and ridicule the early antipoverty efforts with pretentious declarations about the need 'to get people out of poverty, not make them comfortable in their poverty,' as if they had just made a profound discovery, as if nobody had ever thought about that obvious goal," said Bookbinder, now Washington representative of the American Jewish Committee.

In a passionate defense of poverty programs, Bookbinder said that although failures occurred, "What is the big truth to be found in the record of the OEO programs as against the big lies being told about it . . . ?

"Can anybody really doubt that millions of American youngsters are today better off than they might otherwise have been because of Head Start?" he asked. "Take Job Corps . . . take VISTA [Volunteers in Service to America], take Foster Grandparents, take one program after another, and there is indeed much to cheer about."

"Twenty-one years of age is the age of maturity in an individual," said Raul Yzaguirre, president of the National Council of La Raza, a Washington-based civil rights group for Spanish-speaking people.

"It's time we look back and look forward, look at our experiences to see what we can portend for the future," he said. "We want to look at our successes -- Medicare and Medicaid, the decline in poverty among the elderly."

Dorothy Ridings, president of the League of Women Voters, touched a nostalgic high point in a luncheon speech when she said: "Many of you sitting here were probably working on the same issue 20 years ago . . . . You were a lot younger and a lot more idealistic then."

While veterans of Johnson's "War on Poverty" discussed old battles, their reminiscing did not dominate the start of the two-day conference on neighborhoods.

Most participants at the meeting lead community groups throughout the nation that seek to gain political strength and hope to improve job training, education, housing and economic development for the poor.

Several speakers said that while the federal government has retreated on social-policy efforts, community-based groups not dependent on government funding have flourished.

Bud Kanitz, executive director of the sponsoring coalition, said new social-policy activists working against poverty are not "Reaganites" but often echo the president.

"The neighborhood movement takes the rhetoric of the Reagan administration and works with it," he said. "They believe in self-help, family, church-basement meetings -- and they don't depend on the government."