NEW YORK (NYT NEWS SERVICE).- Henry N. Cobb, who in 70 years as an architect — more than half of them in partnership with I.M. Pei — designed some of the country’s most prominent buildings, including Boston’s blue-glass John Hancock Tower, the tallest building in New England, died Monday at his home in Manhattan. He was 93.

His death was confirmed by Ian Bader, a partner at their architecture firm, Pei Cobb Freed & Partners.

A Boston native who could trace his Massachusetts lineage to 1626, Cobb moved to New York in 1950 to begin his career, concluding that his hometown offered little promise.

“I had formed an opinion, not wrong at that time, that Boston was moribund,” he said in an interview for this obituary in 2010. “It was, in my view, self-satisfied, deeply resistant to change.”

And yet over the next seven decades he played a crucial role in remaking the city by designing a series of striking buildings, including the John Joseph Moakley Federal Courthouse, a catalyst in the revitalization of the South Boston waterfront, and the Center for Government and International Studies at Harvard University, where he was chairman of the architecture department from 1980 to 1985.

His greatest mark on Boston is the Hancock building, an 800-foot-tall glass parallelogram that towers over Trinity Church, a beloved Romanesque edifice by the 19th-century architect Henry Hobson Richardson.

Cobb covered his tower entirely in mirrored panels, as if to reflect the church’s ornate architecture on a vast screen. The critic Paul Goldberger, in his book “Why Architecture Matters,” described the tower as self-effacing, “a piece of abstract sculpture; beautiful but mute.”

But when the idea of raising a skyscraper next to Copley Square and the venerable Trinity Church was first announced, in the late 1960s, it “provoked outrage,” Cobb said.

“People told me to my face that we had prostituted ourselves professionally for accepting this commission,” he said.

As the building neared completion in 1972, glass panels weighing up to 500 pounds each began dropping from its facades, endangering pedestrians. The building had to be boarded up — headline writers called it “the plywood palace” — and some Bostonians saw the debacle as “retribution for overreaching,” Cobb said.

The bad publicity and the costs of litigation in the crisis nearly put the Pei firm out of business. Even after replacement glass solved the problem, “we were blacklisted from doing skyscrapers,” Cobb said.

“And then, eventually, people figured that we were still around, so we must be doing something right,” he said. It helped, according to Robert Campbell, the longtime architecture critic of The Boston Globe, that Cobb remained “an absolute model of rectitude and professionalism” throughout the affair.

As the firm rebounded, Cobb focused largely on office buildings, as a confidant of developers and corporate executives. With a few exceptions — he designed the National Constitution Center in Philadelphia and a museum in Portland, Maine — he mostly stayed out of what he called “I.M.’s territory.” Pei, who died in 2019, designed many museum buildings, including the East Wing of the National Gallery in Washington and the Pyramide du Louvre in Paris.

Cobb’s notable projects included the U.S. Bank Tower in Los Angeles (1989), long that city’s tallest; the World Trade Center Barcelona (1999), inspired by a boat; and the Torre Espacio (2008), a Madrid skyscraper that resembles a rocket.

In 2009, he completed the Goldman Sachs headquarters, at 200 West Street in Lower Manhattan, which was widely praised for its discreet elegance, and a dormitory complex at Princeton University, known as Butler College, which replicates the intimacy of the campus’ gothic dormitories but in modernist form. (In recent decades, Cobb shared design credit with several of the firm’s younger partners.)

Cobb did not have the high profile of contemporaries like Frank Gehry or Pei. He called them “formgivers” and himself “a problem-solver.” Yet he was “an architect of immense creativity,” Goldberger wrote, and a major influence on the profession as an educator and mentor. Campbell said that Cobb’s “great intelligence and great integrity” — which he wielded with a gentlemanly manner — “were as important to his status as the buildings he designed.”

Henry Nichols Cobb was born on April 8, 1926, the second of three sons of Charles Kane Cobb, an investment counselor, and Elsie Quincy (Nichols) Cobb. He traced his roots to another Henry Cobb, who was born in Kent, England, in 1596 and landed on Cape Cod in 1626. But his family wasn’t wealthy, Cobb, said, and his mother went to work during the Depression to help support the family.

Still, his parents managed to take him to Europe when he was 9 — a trip, he said, that began his lifelong fascination with architecture. Nine, he said, is the perfect age: “You are mature enough to take a lot in, but not yet preoccupied with yourself, the way you become very shortly thereafter.”

Cobb graduated from Philips Exeter Academy in New Hampshire in 1944, had an accelerated undergraduate education at Harvard College, graduating in 1947, and then studied at the Harvard University Graduate School of Design. As an undergraduate he joined the Navy ROTC on campus.

It was Harvard in the 1940s that he met Pei, who was nine years his senior and who was teaching at Harvard’s architecture school at the behest of its German émigré dean, Walter Gropius. But Pei’s teaching career ended when he went to work for the flamboyant developer William Zeckendorf in Manhattan in 1948. Two years later, he asked Cobb, who had taken a job at a Boston firm, to come work for him.

Zeckendorf, Cobb said, was a “courageous, imaginative, some would say reckless developer” who gave his young architects enormous responsibility.

“He took us to every meeting, in part because he was a great mentor,” Cobb recalled, “and in part because he had a Medici complex — he loved being able to say to people, ‘This is my architect.’”

Cobb was only 29 when Zeckendorf put him in charge of Place Ville Marie, a 4 million-square-foot office and shopping complex in Montreal, its main building standing 42 stories. Cobb said the tower’s cruciform shape was derived from Le Corbusier, one of the most influential modernists of the 20th century.

Pei and Cobb established their own firm with a third partner, Eason H. Leonard (who died in 2003) in 1955; James Ingo Freed (who died in 2005) joined them a year later. The firm was known as I.M. Pei and Associates and later I.M. Pei and Partners. It became Pei Cobb Freed & Partners in 1989, a year before Pei retired. (Pei went on to form Pei Partnership Architects with two of his sons.)

Cobb said that he was always in charge of his own projects — not an underling of Pei’s — but that people tended to attribute buildings to the firm’s best-known partner.

“When you’re working with a superstar, it goes with the territory,” Cobb said. He said the attribution issue — even when Pei tried to clear up misunderstandings — sometimes led to “extreme tensions within the firm.”

A book by Pei, “I.M. Pei: Complete Works,” published in 2009, included none of Cobb’s buildings, which Cobb described as an effort by Pei to set the record straight. Cobb gave his own version of events in “Henry N. Cobb: Words & Works 1948–2018; Scenes from a Life in Architecture,” published in 2008.

The Pei-Cobb partnership was tested by the Hancock building crisis. Cobb said he had accepted the commission from the John Hancock Mutual Life Insurance Co. believing that his intimate knowledge of Boston could help him create a building that would meet one of the company’s “very difficult requirements” — 2 million square feet in a single tower.

He spent more than a year speaking to Bostonians who opposed the building, he said. In 1973, after glass had been falling for months, engineers determined that the problem was caused not by the building’s design but by the fabrication of its windows. Nonetheless, Hancock’s board, determined to avoid future embarrassments, decided that as the building was repaired, each large sheet of glass should be replaced by three smaller panels, separated by mullions.

Cobb believed that the proportions of the building would have been destroyed by the addition of those mullions. In a 1974 meeting, which he referred to as “the hinge-point of my career,” Cobb persuaded the Hancock board to reinstall the glass in its original configuration.

“If you replace the glass as it was designed, some day the problem will be forgotten and you, the Hancock Company, and we, the architects, will be forgiven,” he said he told the board. “But if you subdivide the glass, neither you nor I will ever be forgiven.”

Cobb married Joan Spaulding, a sculptor, in 1953. She survives him, along with their three daughters, Emma, Sara and Pamela, and three grandchildren.

Even in his 80s and into his 90s, Cobb put in long days at the Pei Cobb Freed offices at 88 Pine Street in Lower Manhattan, a building designed by Freed in the 1970s.

Indeed, he was 93 when ground was broken in October on a career-capping project, the International African American Museum in Charleston, South Carolina, a 47,000-square-foot pavilion raised on thick columns. Still under construction, at a waterfront site where slaves were once sold, it is expected to open in 2021. Michael Kimmelman of The New York Times wrote that “the museum’s plain-spoken modernism comes across as almost whisperingly defiant, a turning of the page, promising a deliverance from history, modernism’s originating goal.”

Cobb said he had no regrets about working mostly in the shadow of Pei for 39 years, although he allowed that “some people would say I made a big mistake, that I should have at some point broken away.”

But if he had one regret, he said, it was that he never completed another building that, in his view, was as good as the Hancock tower.

“It was,” Cobb said, “the closest I ever came to poetry.”

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