Nearing the end of his career, death was on Frederick Law Olmsted’s mind.

It was the fall of 1893, and Olmsted, the onetime journalist, farmer, and incisive social critic, had long since established himself as the country’s foremost proponent and shaper of public space. As the father of landscape architecture, he’d created epochal designs for the US Capitol grounds in Washington, D.C., and New York’s Central Park.

Now, 10 years after moving his offices to Brookline, his firm was in the midst of several major commissions, including a variety of park networks and the Biltmore Estate in Asheville, N.C. But as he pondered his own demise, Olmsted exhorted his young partners to focus on “the most important work of our profession now in hand’’: Boston’s Emerald Necklace, his elegant system of parks that tamed the Muddy River, diverting flood waters and sewage, while also lacing together diverse neighborhoods from the Back Bay to Franklin Park and, he hoped, beyond.

“Nothing else compares in importance to us with the Boston work,’’ he wrote that fall in a pair of letters from the Biltmore Estate. “Twenty years hence you will be looking back to Muddy River as I do to Central Park.’’

It is impossible to imagine the Boston of today without Olmsted’s gem-like system of connected parks. The cultivated yet seemingly wild landscapes stretch more than 7 miles, linked by parkways as they snake through large swaths of the city and Brookline, harboring secret paths, sudden vistas, undulating waterways, serene ponds, and verdant refuges.

Olmsted believed parks like these were essential to democracy — and have the delights of open space ever been so vital than during the pandemic? — providing space for solace, health, gatherings, even protests.

Now, as communities across the country celebrate the 200th anniversary of Olmsted’s birth, his park-making legacy has taken on fresh urgency as landscape architects, scholars, activists, and others seek to recast his pioneering vision to help cities meet the steep social and environmental challenges of the 21st century.

“There are some eerie parallels between the historic threads in the late 19th century and now in terms of significant racial and social divides,’’ said Anne Neal Petri, chief executive of the National Association for Olmsted Parks, which is coordinating Olmsted 200, a yearlong bicentennial celebration. “These were things Olmsted was attempting to deal with, which is why the landscape principles behind his parks are so important now.’’

Nowhere is that more true than in Boston, where Olmsted predicted the Emerald Necklace and other area projects would become “points to date from in the history of American Landscape Architecture, as much as Central Park. They will be the opening of new chapters of the art.’’

On the one hand, the city’s park system was a forward-thinking public works project that would harness parkland to help control flooding and mitigate sewage around the Fens — what we’d today call “green infrastructure.’’

On the other, Olmsted employed open space to etch his philosophy into soil, plant, and stone: Free and open parks, he believed, were essential to the physical and spiritual health of a city’s poorer classes. His parks held the promise that every American could access the restorative powers of nature, a mixing of the classes he believed would encourage a shared sense of civic purpose — particularly following the horrors of slavery.

Jen Mergel, director of experience and cultural partnerships at the Emerald Necklace Conservancy, described Boston as the perfect stage for Olmsted’s aspirations — a city he could help shape as it incorporated neighborhoods.

“Olmsted really had a vision, he said: Boston is a mere nucleus of the city that it will become,’’ said Mergel, paraphrasing an 1870 talk Olmsted gave at the Lowell Institute. “Olmsted could do something in Boston that he couldn’t do with the given rectangle of land in New York. He could interconnect all of these neighborhoods and actually heal in a way that he couldn’t do in other cities.’’

It’s an aspiration that today remains unfulfilled, as cities such as Boston struggle to combat rising sea levels, heat islands, and an aging infrastructure built for when car was king. Meanwhile, economic inequality is at historic levels, and renewed calls for racial justice have revealed deep fissures in nearly every corner of American life.

And while egalitarian public space was a first principle for Olmsted, today we tend to honor it only in the breach: We don’t make much in the way of new urban green space, and when we do, location tends to follow the money.

Even the Emerald Necklace remains incomplete — a lost opportunity that still reverberates across the city. Some stretches have been cannibalized for roadways and other urban amenities. Others, such as a planned boulevard along Columbia Road to connect the Emerald Necklace with Pleasure Bay in South Boston, were never built. Where Olmsted imagined a lush parkway traveling through Roxbury and Dorchester, Columbia Road slices through some of the city’s poorer neighborhoods, a gritty streetscape of snarled traffic and sparse foliage.

“The chain was never finalized,’’ said Mergel. “This is a moment to grapple with the questions Olmsted left us. Many of them are still unanswered, and it’s in our hands to move them forward.’’

Park-making was not an obvious career choice for Olmsted, who as a young man worked in dry goods, traveled to China, and eventually ran a farm on Staten Island.

But that began to change during a walking tour of England in 1850. Disembarking at Liverpool, Olmsted visited nearby Birkenhead Park, the country’s first publicly funded expanse, welcoming aristocrats and commoners alike.

Olmsted was astounded by what he saw, later writing: “I was ready to admit that in democratic America, there was nothing to be thought of as comparable with this People’s Garden.’’

“The poorest British peasant is as free to enjoy it in all its parts as the British queen,’’ he wrote in his resulting travel memoir, “Walks and Talks of an American Farmer in England.’’

An equally pivotal moment came a few years later, when Olmsted set out on the first of a pair of reporting trips into the Deep South for a publication that would later become The New York Times. Using the pen name “Yeoman,’’ Olmsted produced a series of sharply observed dispatches on the barbaric institution of slavery. He was struck, too, by the region’s lack of public amenities, such as schools and libraries, solidifying his belief that human bondage remained the country’s main impediment to becoming a great republic.

“What he sees in the South is an impoverishment of the public sphere,’’ said Rolf Diamant, coauthor of the recently published book “Olmsted and Yosemite: Civil War, Abolition, and the National Park Idea.’’ “He’s very much involved in this campaign to prove that the country had not lost its way, that it could become something much better.’’

Even so, there was no clear vehicle for Olmsted’s varied interest in social issues, the natural world, and politics, said Sara Zewde, a landscape architect at Harvard’s Graduate School of Design. “He’s asking himself: How do I triangulate between these?’’

The answer arrived in 1857, when Olmsted, possessing scant obvious qualifications, became superintendent of a swath of public land in Manhattan. The following spring, he and architect Calvert Vaux won the competition to design Central Park. Their design, which drew on the lessons of Birkenhead and Olmsted’s southern travels, was nothing short of a manifesto.

“It’s not about designing a pretty park,’’ said Zewde, founding principal of Studio Zewde in New York. “It’s about designing what he thinks America should be.’’

Diamant, a former superintendent of the Frederick Law Olmsted National Historic Site in Brookline, called Central Park “an enormous departure from anything the country had seen.’’

“It was basically saying: We’re a country that’s capable of major civic investments on behalf of the public good — not on behalf of the wealth of elite slave owners.’’

In addition to his work in New York, Olmsted played a leading role in several major projects in the coming years, including the US Sanitary Commission during the Civil War, which provided medical logistics for Union troops, and he later authored a landmark report on the management of Yosemite Valley.

“That report is in a way a Reconstruction document: It’s looking at the future of the United States as it emerged from four years of Civil War,’’ said Diamant. He added that Olmsted, while making the case that Yosemite should be open to the public, argued for “a series of great public grounds around the country.’’

“It’s the blueprint — the philosophical framework — for the National Parks Service,’’ said Diamant. “He looks at parks as foundational to a renewed and refreshed American republic.’’

Ultimately, the Olmsted firm participated in more than 6,000 projects before closing in 1979, leaving an indelible mark on the country’s parks, university campuses, neighborhoods, and private residences.

Of course, the America of today would be almost unrecognizable to Olmsted, whose agrarian vision of parkland was rooted in small New England towns such as Brookline, where he moved in 1883.

He would likely be flummoxed by calls for more public input in the park-making process: His best-known work, Central Park, uprooted a community of Black property owners known as Seneca Village. His attitude was at times patrician, and his language about ethnic minorities could be demeaning.

Perhaps most ironically, Olmsted’s designs, though conceived in a spirit of egalitarianism, now define some of the country’s most exclusive neighborhoods, including in Boston and Brookline.

“Olmsted’s vision is this equalitarian vision: He really does want everywhere to look like Brookline,’’ said Garrett Dash Nelson, president and head curator of the Boston Public Library’s Norman B. Leventhal Map & Education Center.

“In his view, a neighborhood becoming ‘better’ — what we might think of today as gentrification — was just an unambiguous good,’’ he continued. “So that’s a question: Are public spaces genuinely shared places where we can all come together? Or are they spaces that betray stories of inequality and social division?’’

Those questions lie at the heart of Zewde’s work as a landscape architect.

She recently retraced Olmsted’s travels through the South, hoping to untangle the relationship between slavery, the history of landscape architecture, and her own work. While she encountered many of the same social and economic dynamics Olmsted documented in the 1850s, the physical locations he described have often vanished — obscured by new and unrelated designs.

“A lot of times it was landscape architecture, the profession he’s known for founding, that was used for un-telling those stories,’’ said Zewde. “So a big question for me and my practice is, how can those tools help tell these stories?’’

Similarly, the Emerald Necklace Conservancy and the Frederick Law Olmsted National Historic Site in Brookline have sought to mark the bicentennial with a year-long project they’re calling Olmsted Now. The sprawling effort encompasses a host of programs, including a recently concluded grant competition aimed at equitable programming for parks across the city.

Conservancy president Karen Mauney-Brodek said it became clear following the Black Lives Matter protests of 2020 that the bicentennial could not merely be a celebration of Olmsted’s life.

“It had to be about the principles, and how they could be better integrated into the landscapes and the city,’’ said Mauney-Brodek, whose organization has sought to collaborate with a diverse cohort of residents and community groups from neighborhoods abutting Franklin Park. “It just became clear that we needed to assume we didn’t know everything.’’

Stephen Gray, an associate professor at Harvard’s Graduate School of Design, helped the Conservancy plan its approach to the bicentennial.

“It’s got to be about identifying the next generation of urban thinkers and actors,’’ said Gray, who also leads the design firm Grayscale Collaborative.

Just beyond a rusting stretch of overpass, the elegant stone bridge lies sunken in what is perhaps the state’s most pitiful park: Charlesgate, the crumbling tangle of roads between Kenmore Square and Back Bay that connects Storrow Drive to Boylston Street, traversing the Massachusetts Turnpike along the way.

The complex system of on-ramps and overpasses, a punishing hangover of mid-20th-century design, chokes off some 12 acres of parkland in the heart of the city, while also killing the Muddy’s estuary, forcing the tributary underground and severing it from the nearby Charles River.

It’s a far cry from the arboreal linchpin Olmsted originally designed for the area, connecting the Emerald Necklace to the Charles and Commonwealth Avenue.

But that may be changing: Two bridges that dominate the landscape are nearing the end of their functional lives, offering a rare chance to reclaim green space in central Boston.

“If it’s done the right way, we can unlock acres of new parkland in Charlesgate,’’ said Marie Law Adams, whose firm, Landing Studio, has been working with the Conservancy, Charlesgate Alliance, and the Massachusetts Department of Conservation and Recreation on a new design for the area.

By elevating the area’s roadways, she said, their design would “daylight’’ the Muddy, reestablishing its connection to the Charles, while also creating a pedestrian-friendly park system that links the Emerald Necklace to the Esplanade and Commonwealth Avenue, ultimately leading to the country’s oldest public park, Boston Common.

“The Emerald Necklace was the genius breakthrough of thinking about [parks] as ecological infrastructure for cities — how you could use natural systems to create a sustainable, healthy environment,’’ said Landing Studio cofounder Dan Adams. He added that their design draws heavily on Olmsted’s original principles: “We’re looking to a pinnacle philosophy in the 19th century, and trying to jump over a series of mistakes from the 1950s and ‘60s to think about the future.’’

To that end, the Adamses are using many of the same tools as Olmsted — namely trees, plants, and soil — if perhaps more strategically deployed given the site’s crush of cars, its decades of pollutants, and the mounting effects of climate change.

“We have to sort of supercharge the landscape,’’ said Dan Adams, who also directs the architecture school at Northeastern University. He described each tree as “a piece of infrastructure.’’ “We need them to cool down the city. We need them to clean the air and filter water.’’

And while there’s no returning to the Charlesgate of old, the Adamses plan to preserve at least one key element from Olmsted’s era: the small bridge that now lies sunken where the Muddy’s waters are forced below ground.

Known as the Fens Pond Bridge, the old bridle path once marked the edge of Boston, a city Frederick Law Olmsted, more than a century in the grave, continues to shape.

Malcolm Gay can be reached at malcolm.gay@globe.com. Follow him on Twitter at @malcolmgay.