"Five years ago, in most cities, minority leaders and historic preservationists stared at each other across a tense communications gap," said Michael L. Ainslie recently.

"Now we realize that there is more to a historic district than rising property values and Sunday supplement features.

"Preservationists are beginning to speak the language of social need."

Ainslie, 36, is a Cincinnati corporation man, a developer of historic properties, former urban renewal aide to Mayor John Lindsay of New York and, since last July, president of the National Trust for Historic Preservation.

He is working hard to change the Trust from a sentimental guardian of old buildings and historic places to the tough catalyst for the recovery of old cities and livable neighborhoods.

Or rather, Ainslie is working to put the Trust in the lead of a growing citizens' movement in America, which is picking up where modern architecture failed. Modern architecture set out to rebuild "the total man-made environment" for automobility and technology. The citizens' movement is fighting for a more human and humane place to live.

Until a decade or so ago, historic preservation in this country was chiefly a concern of white upper-middle-class patriots and architecture buffs. They ran "societies" and worried about deteriorating plantation houses, quaint Federal cottages George Washington might have slept in, sumptuous millionaire mansions and benefit teas with lectures on pewter candlesticks.

Georgetown and Beacon Hill were still deteriorating slums.

Popular interest in the country's past urban life was first aroused, I suppose, when, in 1907, the Rev. Dr. William A.R. Goodwin, rector of Bruton Parish in Williamsburg, Va., set out to restore his church. He became concerned about the sorry state of his town, which was sinking out of sight into a desert of parking lots filling stations and weed patches.

In 1927, Dr. Goodwin had persuaded John D. Rockefeller Jr. to visit. A few decades and $65.5 million later, Colonial Williamsburg was restored for posterity. It also became the country's foremost tastemaker, littering Suburbia, U.S.A., from coast to coast with Federal dormers and Colonial stable lamps.

Old buildings became acceptable -- as long as they were Colonial. Victorian structures were often torn down, to be replaced with Phony-Colonial, 10-story office buildings or split-level ramblers.

Genuine historic charm was on welfare in those days. Occasionally, an exceptional architectural treasure became the subject of high society charity. Led by architect Philip Johnson, for instance, everybody who was anybody came to picket at McKim, Meade and White's magnificent Pennsylvania Railroad Station in New York in 1963 to prevent its demolition. The pickets carried their protest signs long enough to get their pictures taken but not long enough to build popular support. They had no political clout.

At about that time, local citizens began to become concerned about their historic communities, the tout ensemble, rather than isolated buildings. They took preservation out of the museum, as it were, and into their daily life.

One of the leaders of these modern preservationists is Leopold Adler II.

He is a lawyer from Savannah, Ga., who found a way to make restoration pay for itself and eventually for the economic recovery of his town. His Historic Savannah Foundation bought an antebellum house just before the wreckers got to it for its used brick. People were crazy about new houses made of old brick in those days.

Adler restored the house and sold it, using the profits to buy and restore more. In a few years, the foundation's revolving fund turned the whole old town center of 800 houses into a national celebrity and tourist attraction. Even the local merchants and politicians, always the last to see a good thing, finally began to support the effort. Old Savannah was made a historic district with strict architectural controls.

But no wealthy historic district is an island unto itself. A restored historic neighborhood is never safe from blight until blight itself is removed. With the help, and for the benefit, of black, low-income residents, Adler's Savannah Foundation is now busy rehabilitating some 600 of their Victorian slum houses at the edge of the old town.

Another community restoration pioneer is Arthur P. Ziegler Jr. and his Pittsburgh History and Landmarks Foundation.

Ziegler's first triumph, in 1964, was the restoration of about 200 fancy Victorian houses in the Mexican War Street neighborhood on the south side of Pittsburgh. He did it with private money -- a revolving fund such as Adler had used -- and without displacement. The neighborhood remains racially and economically mixed.

From there, Ziegler went on to the Manchester neighborhood where, later in the '60s, he used federal urban renewal funds for the country's first historic restoration project for low-income black families.

Now Ziegler and his foundation are busy on Pittsburgh's river front, building Station Square, a residential, recreational and commercial complex with the restored Pittsburgh and Lake Erie Railroad station as its glorious, Beaux Arts centerpiece.

This unusual and, I hope, trailblazing project is privately financed to the tune of some $250 million. The developer is the nonprofit Pittsburgh History and Landmarks Foundation, which got special Internal Revenue Service permission to buy and sell property. All proceeds will be used to finance the further recycling of residential Pittsburgh.

While Ziegler's is the first such downtown business district project, similar citizen action is transforming downtown neighborhoods in a steadily growing number of old cities across the country. The movement is immeasurably helped by national citizen organizations such as Preservation Action, an energetic lobbying group, and the National Center for Preservation Law, which helps with legal matters.

It is hard to tell whether citizen groups, like Adler's and Ziegler's, changed the country's attitude toward old buildings and cities, or whether a changing national mood has produced people like Adler and Ziegler.

The movement, at any rate, is still gaining in strength and sophistication.

It is not only revitalizing old towns and neighborhoods, but also the old National Trust for Historic Preservation. Michael Ainslie is the most visible evidence.

The Trust is an important voice in Congress, in the state legislatures and in corporate boardrooms across the land. It is a source of both public and private funds. It is a respected authority in its field.

It is therefore important when the new president of the National Trust tells his constituents across the country to get involved in neighborhood programs and to help minorities and ethnic groups to turn their communities around.

The proverbial old ladies in tennis shoes are joining forces with youngsters in T-shirts and cornrows.