Pierre S. du Pont’s farm becomes Longwood Gardens, a conservation landmark

From one farm to a public landmark

Pierre S. du Pont bought a 202-acre former Quaker homestead outside Philadelphia in July 1906 for a purpose that sounds simple and still feels radical: he wanted to save the trees from being sold for lumber. He was 36 years old when he made the purchase, and in the years that followed he turned that act of preservation into a landscape built for beauty, hospitality, and public life. In a letter soon after, he said he had bought “a small farm” and hoped to restore it and make it a place to entertain friends.

That first decision became the seed of Longwood Gardens, now a major regional attraction in Kennett Square, Chester County, Pennsylvania, in the Brandywine Valley. Longwood describes itself as a place where the “joy and inspiration” of nature, conservation, and learning come together, and its scale now reflects that ambition. The property spans more than 1,100 acres, with gardens, woodlands, meadows, fountains, and conservatories shaped into one of the world’s great cultivated landscapes.

How the garden took shape

The first major garden at Longwood appeared in 1907, when du Pont laid out the 600-foot Flower Garden Walk. That early design matters because it shows how the estate evolved from a private rescue mission into a deliberate garden-making project, one built not just to preserve what already existed but to add new forms of horticultural expression. Over time, the original farm was transformed into a destination where plant collections, architecture, and public visitation could coexist.

Longwood says conservation has always been at the core of its mission, and the numbers show how far the estate has moved from a single family holding. Before the latest expansion, the garden welcomed about 1.6 million visitors annually. It is now described as the most visited paid public garden in North America, a distinction that places it among the most important cultural sites in the region as well as one of its most heavily used public green spaces.

Longwood Reimagined and the new scale of the garden

The newest chapter arrived with Longwood Reimagined: A New Garden Experience, which opened to the public on November 22, 2024. The $250 million project unfolded over seven years and added new buildings and landscapes across 17 acres, marking what Longwood called the most ambitious revitalization in the garden’s 100-year history. Rather than replacing the estate’s identity, the expansion was designed to update it for a new era of sustainability and garden design.

At the center of that effort is the new 32,000-square-foot West Conservatory. Designed by WEISS/MANFREDI with gardens by Reed Hilderbrand, the building gives the estate a contemporary architectural anchor while staying within Longwood’s larger horticultural mission. The project’s significance goes beyond a single structure: it shows how a historic garden can be renewed without losing the sense of continuity that makes it meaningful in the first place.

The expansion also reinforces Longwood’s role as a destination that serves more than sightseeing. A garden on this scale functions as a place for environmental education, public gathering, and restoration, and those roles have become increasingly important in a region where access to open space can shape quality of life. In that sense, Longwood is not just a preserved estate. It is a working model of how curated nature near a city can meet cultural, ecological, and mental-health needs at once.

Conservation, access, and the public good

Longwood’s story is especially revealing because it sits at the intersection of private wealth and public benefit. Du Pont’s fortune made the original preservation possible, but the estate’s long-term value now comes from how widely it is shared. The garden’s more than 1,100 acres provide room for living collections, seasonal display, and carefully managed landscapes, while its scale draws millions of visitors who experience the site as a regional commons rather than an elite retreat.

That public role has expanded alongside the institution’s conservation footprint. In 2024, Longwood acquired Longwood at Granogue, a 505-acre cultural landscape near Wilmington, Delaware. The purchase extends the organization’s reach deeper into the region and signals that its mission is no longer confined to one historic property. It is becoming a broader landscape strategy for the Brandywine Valley, one that links horticulture, stewardship, and public access across multiple sites.

A landscape with a deeper history

Longwood also emphasizes that the land predates du Pont by thousands of years. For generations, the Lenni Lenape people fished its streams, hunted its forests, and farmed its fields. That history matters because it broadens the meaning of the site beyond the familiar story of an industrialist who loved trees. The land was already a lived-in, managed environment long before it became an American estate garden.

Bringing that history into view changes the way Longwood should be understood. It is not only a monument to one man’s vision or one family’s wealth. It is also part of a longer story about who has shaped this land, who has used it, and who gets to enjoy it now. In a country where public green space is often unevenly distributed, Longwood stands as an example of how a private estate can be remade into a shared civic asset, with conservation, culture, and access all rooted in the same ground.

Longwood’s evolution from a 202-acre farm into a 1,100-acre destination shows how an act of preservation can grow into a public institution. What began as one man’s effort to save trees has become a landscape that helps define how Americans near cities experience nature, and how a historic estate can continue to matter by serving the public well.