A lot has changed since then. In Amherst, Massachusetts, where I live today, Emily Dickinson’s grave site shares attention with newly restored headstones of veterans of the Massachusetts 54th, the African-American “Glory” regiment in the Civil War, segregated in a corner of the cemetery. Some of those men now have pride of place alongside the poet at the center of a 100-foot-long mural of Amherst history facing the cemetery.

In Holyoke, Massachusetts, the preservation of the city’s industrial heritage is not couched so much in aesthetic terms but in terms of climate change: By saving those sturdy paper industry buildings from the 19th century and taking advantage of the cheap, clean energy produced by the 150-year-old canal system, the city sees preservation as the ticket to a more economically vibrant and environmentally sustainable future.

In Boston, a community land trust created by the Dudley Street Neighborhood Initiative anchors affordable housing in Roxbury. New transportation is boosting investment and easier access to downtown but not the familiar social upheaval. Because the land trust maintains in perpetuity the affordability of the 225 homes in the trust, gentrification is blunted. These homes may not be architecturally distinguished, but as the core of a social preservation effort, they are extraordinary.

Clearly, it’s not your grandmother’s preservation society. But as with all families, it is hard to disentangle ourselves from our grandparents’ DNA. The preservation world built by our ancestors is deeply rooted in our cultural life, not to mention our laws and regulations. The problem is that the sources of preservation’s successes are also the obstacles that will hold it back. Filial piety should not prevent us from seeing that there are some things deeply wrong with the preservation movement and the world it has created. It will take a young and feisty generation to continue moving preservation in a new direction.

The 1966 Act established the National Register of Historic Places and the process by which individuals, cities, and states could add important places to the Register. It demanded that every state have a preservation officer, it spurred the creation of local historic commissions, and it established guidelines for standards of preservation and rehabilitation. Later additions included tax incentives to encourage professional rehabilitation. The power to compel preservation is weak — listing on the National Register conveys absolutely no power to preserve, and most towns have little more than the ability to delay demolition of historic properties. Only true local historic districts, which are rare, have the power to restrict changes to buildings. But preservation is now seen as an integral function of local government and a subject of regular community debate.

This architecture-centric approach to preservation has blossomed. There are now more than 100,000 properties on the National Register — Beacon Hill, sure, but also the South End, Quincy Market, Lowell’s mills, and colonial homes all have been saved, drawing investment. The preservation movement gets its share of credit for encouraging a wider appreciation of the past and spurring a return to the city, with all its ordinary glories — the walkable neighborhood, the local triple-decker and the brick row house, the high density that anchors a vibrant community.

Still, the mainstream preservation movement remains consumed with architecture— with saving what is considered beautiful and preventing the construction of what could be considered ugly. The preservation movement created in 1966 was a reaction to decades of massive urban renewal and wholesale dismissal of the past, built, as critic Paul Goldberger has written, “as much out of fear of what would be built as out of love for what people were trying to preserve.” In communities across the country, preservationists have too often devolved into fussy squabbles about the appearance of new windows and the color of shingles. They have worked to protect the homes of wealthy people, while allowing for the demolition of homes and neighborhoods of the working classes and wiping away the layers of history that make places meaningful.

For much of the past 50 years, preservation has been concerned primarily with places of celebratory history. Only very recently has it been pushed to preserve “difficult places” — the sites where slavery and segregation, violence and even genocide, have taken place. A whole ecosystem has been built around the “curatorial management of the built environment,” in the words of James Marston Fitch, one of the fathers of modern preservation. It has tried to emulate the museum approach to preservation of precious objects. But what does that do to history that lacks architectural gems? Is the Shockoe Bottom slave market site in downtown Richmond, Virginia — intentionally paved over by Interstate 95 — to be ignored because the site lacks “integrity,” according to the US Secretary of the Interior’s standards for preservation?

The intersection of Columbus Avenue and Appleton Street in the South End on a sunny summer 2015 morning, inset with the 1885 view of Rainy Day, Boston by Childe Hassam. Photo: Thomas Urell/Stoltze Design

Scarred by the demolition of Pennsylvania Station (and versions of that debacle across the country), the preservation movement has done a lot to save old places and surprisingly little to tell the stories of those places. Few have engaged writers and artists to communicate the meaning of places of architectural and historical significance. Better to spend the money getting the original paint color just right rather than spend it creatively telling the story of what actually happened there!

Finally, the preservation movement is too often in bed with developers, a handmaiden to real estate development that allows for an appearance of preservation but in fact paves the way for displacement in favor of the wealthy. Preservation organizations celebrate the restoration of neighborhood homes, even if the entire community that once lived there has gone running for lower rents. The façades look spectacular, but the community is missing. Far too often, preservation has been just another tool for enshrining the inequality that is the stamp of our age.

What would a progressive preservation movement for the next 50 years look like?

The exciting — if uneven — changes we are seeing in preservation are products of a new world, unimaginable by the drafters of the 1966 law. The greatest wave of immigration to this country, exceeding even the mythical migration of the late 19th century, was only just beginning. Millions of Asian and Latin American migrants have since joined the American polity and are now maturing into major political and cultural forces, demanding their place in our national story.

Economic inequality in 1966 was in decline, the product of economic growth and War on Poverty policies. No one would have predicted that 50 years later inequality would be as great as during the rapacious Gilded Age of the late 19th century. When Jane Jacobs advocated for preserving the small blocks and tenement buildings of her Greenwich Village neighborhood in The Death and Life of Great American Cities, she assumed a broad middle class and public investments that could maintain, off into the horizon, a mixed-income neighborhood. She couldn’t have predicted that her neighborhood would become something of a Potemkin Village, home to a new elite, with her own modest home from the 1950s lovingly preserved by law — but selling for $3.5 million.

The early environmental movement was focused on the spoliation of our natural environment — the pollution of smokestacks, the poisonous dumping of toxic garbage. But big cars and 30-cent gas was the norm, and virtually no one was thinking about how we might be causing catastrophe by warming the earth or that its effects would begin within a few short decades. Preservation was about beauty and buildings, not an unknown problem that would come to be called climate change.

A progressive preservation movement can be built out of these changes.

First, for preservation to flourish it has to stop being exclusively about architecture. Only when we place a full understanding of history and communal meaning at the center of preservation work will the movement tell the complete story of a more diverse America. Rather than ask, “What style is this house?” we should ask, as Tom Mayes of the National Trust has written, “Why do old places matter?”

Second, saving historic sites and reusing them must be a cornerstone of environmental sustainability. Nearly half of all greenhouse gases are produced in the construction, demolition, and operation of buildings. How can the preservation movement join the conservation movement to achieve more sustainable communities? The answer will in part lie with examples from the past, including the Trustees of Reservations (older than Britain’s National Trust) and the Society for the Preservation of New England Antiquities (SPNEA, now Historic New England). For the preservation movement to fully embrace its role in the fight against global warming, we need to jettison some of our concern with aesthetics. This means changing what we mean by “value” in old places. We should save and reuse old buildings because demolishing them contributes to the problem of climate change, no matter how high the LEED rating of their replacements.

The demands of a sustainability ethos ask us to abandon a museumish approach to architectural “integrity” while embracing layers of old and new, interwoven in a single building or landscape. Paradoxically, progress requires older ideas, or ideas from other cultures, where we accept layers of time, are more flexible on “authenticity” and “integrity,” and value the architecture of adaptive reuse. Spend a week in Rome, where you might sleep in a Renaissance palazzo, have dinner at a restaurant carved out of a mountain built of ancient amphoras, and drink from a 19th-century fountain, and you’ll recognize how much more comfortably other countries interact with their pasts.

At the same time, we will have to be more concerned with history, not less. One of the most exciting developments in historic preservation in the past quarter century has been the steadily growing interest in understanding the pain that inheres in difficult places, places of suffering and national disgrace, and sites of conscience. To help create greater unity in a stunningly diverse nation of immigrants, preservation must bring us face-to-face with the legacies of our controversial pasts. This courageous stance has already helped to infuse new life into the preservation movement, provoking dialogue at places such as the Tenement Museum in New York, the Manzanar Japanese-American internment camp in California, and newly interpreted slave plantations across the South.

Perhaps most thorny of all, preservation will have to show that it is a path toward economically just communities. If we care about creating dense cities and towns, but reject the re-sorting of cities by class that takes places in gentrifying historic districts, we will have to offer a new model for saving buildings and communities. That means embracing public housing as well as new forms of property ownership, such as community land trusts and mutual housing, as a way to protect against waxing and waning tides of private investment. It means passing ordinances such as one in San Francisco that provides financial support to preserve essential long-standing community businesses. It means making mainstream the kind of work Historic Boston does to restore dilapidated structures as the basis for local economic development. And it means returning the “movement” to the preservation movement by taking to the streets to protest displacement in alliance with others. When the grassroots tenants rights organization City Life, in Boston, conducts acts of civil disobedience to prevent low-income residents from being evicted by multinational banks, they are acting as preservationists. Traditional preservation organizations should stand with them.

This is preservation’s moment. It can finally shed its reputation — partly deserved — as elitist, the domain of the rich, standing in the way of progress, obsessed with architecture. And it can suddenly find itself offering solutions to some of the most pressing problems of our day, crafting a sustainable approach to climate change, honestly confronting our difficult pasts, and reclaiming a more equitable society.