Cohn, who was at International Creative Management since its inception in 1975 and headed the New York office for nearly 25 years, died Wednesday at New York-Presbyterian Hospital after a brief illness, said family friend David Richenthal, a Broadway producer. The family did not disclose the nature of the illness.
During his more than three decades at ICM, Cohn represented an array of actors, directors, writers, playwrights and composers.
Over the years, his long list of clients included Paul Newman, Woody Allen, Meryl Streep, Robin Williams, Whoopi Goldberg, Susan Sarandon, Lily Tomlin, Nora Ephron, Bob Fosse, Robert Altman, Mike Nichols and E.L. Doctorow.
Dubbed by Time magazine in 1993 "the first super agent of the modern age," Cohn was "a finger-in-every-pie packager who represented the writer and the director and the stars of a given production."
A decade earlier, a New Yorker profile noted that in 1981 "ten feature films and nine Broadway or off-Broadway plays opened that were written, directed or produced by one of his clients or in which a Cohn client had a major acting role."
Cohn also was known for getting Columbia Pictures to pay a record $9.5 million for the movie rights to the Broadway musical "Annie."
"When I first met Sam as a young producer and asked him why he had become an agent, his answer was very to the point," Richenthal said. "He said, 'I like being on the side of the artists.' And I think that certainly summarized his work point of view. He wanted to be an advocate for great artists."
Added Richenthal, who worked with many of Cohn's clients, including Arthur Miller: "He was probably the smartest man I've ever known. He did cut a large swath through the industry just by the dint of his intelligence."
He did so with an eccentric flair.
In show business circles, the quirks of the Princeton- and Yale Law School-educated Cohn were as well known as his talents as a power broker.
Shunning the typical well-tailored look favored by most agents, Cohn was given to sporting a wardrobe that the New Yorker described as "a bit frayed": a lot of sweaters, threadbare at the elbow; old, cuffed trousers that were a tad too short; Gucci loafers, from which he had removed the buckles with a razor blade.
"As rude as he was astute," as a Daily Variety writer once put it, Cohn also was known for not returning phone calls, including those from movie executives, producers and even fellow ICM agents.
Perhaps most famously, he had the nervous habit of chewing paper -- pieces of notes, plays, screenplays, newspapers and magazines.
Even matchbook covers, recalled director Arthur Penn, who would have lunches with Cohn about once a month at the Russian Tea Room in the late 1980s, when Cohn was his agent.
"He was an eccentric, certainly," Penn told The Times on Thursday. "But he was a superb agent in the theater, where everybody is looking for a piece of the gross. He was rather ingenious in devising ways to cut up that gross, with ever so many participants. That was one of Sam's really remarkable abilities."
And, Penn recalled, "he loved to, after the theater, assemble a group of people and sort of have a great old round table. And usually something creative came out of that."
A die-hard New Yorker, Cohn in his prime reportedly saw at least 100 movies and 75 plays a year, in addition to spending nights at the opera and at concert halls.
Conversely, Cohn detested Los Angeles and rarely came to the West Coast; and on those rare occasions when he did, he'd return to New York as quickly as possible.
Born May 11, 1929, in Altoona, Pa., to a family that owned the Independent Oil Co. of Pennsylvania, Cohn attended the Culver Military Academy in Indiana as a teenager.
After majoring in English and German literature at Princeton, he had a two-year stint as an Army lieutenant based in Japan. He graduated from Yale Law School in 1956 and launched his career at CBS, first in the legal department and then in business affairs.
After leaving CBS in 1959, he made a brief attempt to become a television producer. But he returned to law in 1961 when he became an associate of the law firm of Marshall, Bratter, Greene, Allison & Tucker and soon became third partner in the firm's entertainment law department.
Cohn later became one of the attorneys for the talent agency General Artists Corp., and in 1965 he assembled a group of investors to purchase the agency for which he became one of the managers.
In 1968, he merged General Artists with another agency, Creative Management Associates. And in 1975, Creative Management merged with International Famous Agency to form International Creative Management.
In 1999, Cohn relinquished his management role at ICM, but he continued working as an agent. He retired in February.
He is survived by his wife, Jane Gelfman; his daughter, Marya; his son, Peter; and four grandchildren.