William Zinsser, the former Yale writing teacher, master of Branford College and famed author of “On Writing Well,” died on Tuesday in his Manhattan home. He was 92 years old.

Zinsser, who arrived at Yale in 1970, authored 19 books over the course of his life. His most famous, “On Writing Well,” is a celebrated guide to concise, clear and well-crafted writing. The book has sold over 1.5 million copies worldwide, in addition to being a staple in the English Department at the University. “On Writing Well” was used in 14 of the 21 sections of “Reading and Writing the Modern Essay” for the 2014–15 academic year, according to English lecturer Fred Strebeigh.

“Writing is hard work,” Zinsser wrote in the classic book. “A clear sentence is no accident. Very few sentences come out right the first time, or even the third time. Remember this in moments of despair. If you find that writing is hard, it’s because it is hard.”

A journalist, essayist and editor, Zinsser spent many years serving as the executive editor of the Book-of-the-Month Club, drama editor and movie critic for The New York Herald Tribune and editor of Yale Alumni Magazine. But to his students he was, above all, a beloved teacher and friend — offering his students edits and advice long after he finished teaching at Yale.

In 1970, Zinsser created his “Nonfiction Workshop” course — the first of its kind at the University.

At the time, Zinsser’s way of teaching writing was novel for a University steeped in tradition.

“In the 1970s, when Bill came, this was a time when the idea that you would teach people something useful in writing was very frowned upon,” said Mark Singer ’72, a student of Zinsser’s and staff writer at The New Yorker. “It was a revelation to most of the people in the class.”

Corby Kummer ’78, another student of Zinsser’s and a senior editor at The Atlantic, echoed Singer’s statement — noting that during this time period, the Yale English major primarily focused on literature. Writing was considered to be vocational, and “beneath the dignity of a Yale English student,” Corby said.

But in its first semester, 170 students signed up for “Nonfiction Workshop,” despite the fact that it was capped at 15 students.

Roger Cohn ’73, a member of Zinsser’s first class and editor of Yale Environment 360,  said the class was first taught as a college seminar. The course proved so valuable to students that it soon became a regular course, Cohn added.

For the nine years Zinsser taught the course, it remained overwhelmingly popular at Yale, as Zinsser encouraged his students to write, edit and rewrite again, in order to eliminate unnecessary “clutter” from their work.

Zinsser hammered into his students the idea that, with good writing, less is more, said Kevin McKean ’74, a student of Zinsser’s and editorial director of Consumer Reports said.

He taught his classes to write “clearly” and “concisely,” encouraging his students to cut out the “purple prose,” said Roanne Mann ’72, another student of Zinsser’s who now serves as a federal judge.

“The overwhelming sin was clutter,” Zinsser wrote in a feature for Yale Alumni Magazine in 2009. “It was in that Yale class that I became a fierce enemy of every word or sentence or paragraph in a piece of writing that wasn’t doing necessary work.”

Dan Denton ’75, a student of Zinsser’s and founder of several magazines, described Zinsser’s class as a “life-changer,” cutting through the fog of term paper style to show students the way to better writing and clearer thinking. Zinsser assigned a different type of article every week, Denton said, ranging from from profiles to editorials to interviews. Each would be returned the following week with red pen notations — brackets around vague or unnecessary phrases, alternatives to consider and arrows moving around paragraphs, Denton said.

John Rosenberg ’75, editor of Harvard Magazine, described his first few weeks in Zinsser’s class as “almost traumatic.”

“During the first couple of weeks, then, one often got an assignment back with clear indications that the five pages or so of lovingly crafted prose could more effectively be rendered in four, or three, or two,” Rosenberg said. “That that brilliant lead could best be junked entirely — the first two or three or four paragraphs might be no more than throat-clearing, with the real text beginning a page or two into the draft.”

Rosenberg said that after weeks of this severe paring down of papers, students began to find their own voices, rather than trying to imitate someone else’s. Zinsser’s students knew that for all the time they spent writing their drafts, Zinsser spent at least an equal amount of time marking up the papers and suggesting edits, Rosenberg said.

He added that it was the most attentive, personal teaching he has ever experienced.

Zinsser’s influence has also extended beyond the students who took his class to the English Department as a whole.

“Bill Zinsser’s impact on nonfiction-writing teachers and students at Yale continues to be strong because he transformed his nonfiction course, which he created at Yale and taught here from 1970 to 1979, into ‘On Writing Well’ — a book that puts the wisdom and humor of Bill’s course into 140 pages,” said Strebeigh, who also took Zinsser’s class. “A majority of teachers in our many sections of English 120 assign the book, and not just because it gives good advice.”

The strength of “On Writing Well,” Strebeigh said, is in Zinsser’s effort to select paragraphs by great writers, and then teach his readers how to learn from those writers. This teaching vision fits with the English Department’s focus on strong reading of strong writing, Strebeigh added.

Anne Fadiman, English professor and Yale’s Francis Writer-in-Residence said Zinsser has also influenced a nonfiction writing course she teaches at Yale.

“Bill has a had a huge influence,” Fadiman said. “During all ten springs that I’ve taught English 455 — ‘Writing about Oneself’ — we’ve read his book ‘Writing About Your Life,’ a guide to first-person writing, and absorbed his advice on cogency, unpretentiousness and the confidence to sound like yourself.”

In addition to teaching people how to write, Fadiman said, Zinsser was an example of how to live. His optimistic attitude pervaded everything he did, she said. In “Writing about Oneself,” Fadiman said, the reading and writing each week has a theme. In the Zinsser week, the theme is joy.

Zinsser also served as Master of Branford College from 1973 to 1979. Lorenzo Simpson ’73 GRD ’78, whose deanship of Branford overlapped with Zinsser’s tenure as master, described Zinsser as a warm person who was “striking” in his lack of pretense.

“He often joked about being one of the very few masters with neither a Yale degree nor a PhD,” Simpson said.

Zinsser, who was born in Manhattan in 1922 and later attended Deerfield Academy in Massachusetts, graduated from Princeton in 1944. His time at Princeton was interrupted by World War II, in which he served in the Army in North Africa and Italy.

Christopher Buckley ’75, an author and student of Zinsser’s, described Zinsser as “sweet-souled,” “self-deprecating,” and more interested in his students than in himself. It was only after reading an obituary of Zinsser published in The New York Times that Buckley learned about Zinsser’s time in the war. Not once did Zinsser mention that, Buckley said.

Zinsser left Yale in 1979 to return to New York, where he continued teaching students how to reduce clutter from their writing at The New School and the Columbia University Graduate School of Journalism.

As his glaucoma advanced, Zinsser found himself forced to leave the classroom, but never stopped teaching and mentoring his students.

Lawrie Mifflin ’73, a student of Zinsser’s who went on to become the first female sportswriter for The New York Daily News, said that when she and her friend heard that Zinsser was losing his sight, they went to go visit him again. Mifflin told Zinsser that she had been toying with the idea of writing a memoir, and Zinsser offered her advice and encouragement.

Mifflin later found out that Zinsser had been editing his students’ pieces and helping them with their books, even as he approached the end of his life.

“I thought that was such a beautiful thing,” Mifflin said. “When he couldn’t see anymore he was still helping people with their writing.”

Zinsser also remained active at Yale until his eyesight made it difficult for him to travel to New Haven, paying a visit to Fadiman’s course each spring for several years. Afterward, until his health began to fail, he invited students of Fadiman’s class to visit him at his office in New York and ask him questions about their writing.

“In addition to warmth and lack of pretension, Bill’s most salient characteristic was his desire to be useful,” Fadiman said. “During the phase when students came to New York to see him in his office, he didn’t want them to visit him to pay homage; he wanted them to come with specific literary problems that he could help them solve.”

Zinsser was not an austere, distant or remote figure, Rosenberg said. He was a stern craftsman, but a remarkable maker of human connections and friendship for many people over many decades.

Janice Kaplan ’76, a student of Zinsser’s and editor of Parade, said he was the most influential teacher she has ever had.

“I’m tempted to say, ‘They don’t make them like Bill Zinsser any more,’ only I can see his red pen comment in the margin: ‘Avoid cliche,’” Buckley said.

Zinsser is survived by his wife Caroline, his son John, his daughter Amy and four grandchildren.