William Backer, a major figure in American advertising and a principal creator of one of the most indelible of all commercials, the 1971 TV spot in which a vast and fresh-faced youth chorus sings with guileless enthusiasm, “I’d Like to Buy the World a Coke,” died May 13 at a hospital in Warrenton, Va. He was 89.

The Piedmont Environmental Council, a Warrenton-based conservation group where Mr. Backer had been president since 2004, announced the death. His wife, Ann Mudge Backer, said the cause was complications from colon cancer surgery.

Advertising has long been regarded as one of the most characteristically American of occupations — a blend of sentiment and salesmanship, of craft and commerce that can at its best rise to the level of art and become a part of the lives and cultural heritage of millions.

Among the campaigns that met that description were several for which Mr. Backer received significant credit. One enticed much of America to kick back and enjoy “Miller Time.”

An aspiring songwriter in his youth, Mr. Backer deployed words and music, indelibly linking the softly sentimental strains of “Here’s to good friends, tonight is kind of special” with Löwenbräu in commercials remembered by legions of beer drinkers.

Bill Backer at his horse farm in The Plains, Va. (T.J. Kirkpatrick)

Mr. Backer was associated with other celebrated advertising campaigns, including one for Miller Lite that in its heyday seemed as amusing and entertaining as any that had ever appeared. In its individual spots, entertainers and leading sports figures such as Billy Martin and George Steinbrenner showed up to engage in sometimes fierce arguments over the merits of a light beer.

Some touted its appeal to the palate: “Tastes great.”

Others assumed the roles of partisans of its low caloric content: “Less filling.”

The apparent fervor of the debate and the popularity of the participants, who had won their fame in arenas other than acting or sales, made the campaign a cultural landmark.

For all his other successes, few commercials made for radio or television seemed to tug at the heartstrings more than the Coca-Cola advertisements Mr. Backer helped bring forth in 1971. The work simultaneously produced a sense of international goodwill — the singing youth are on a hilltop, dressed in their indigenous clothing styles and holding Coke bottles — and a recognition of the soft drink’s global penetration.

[Original 1971 Coke commercial]

The commercial gained renewed attention last year when it was used in the finale of “Mad Men,” the acclaimed AMC cable series set in the 1960s advertising world. As the last episode closed, the Coke advertisement came as a brainstorm to the principal figure, Don Draper (Jon Hamm), as he sat meditating at a California spiritual retreat.

The implication was clear: Draper, having endured many obstacles and impediments, had reached his creative apex. (Mr. Backer indicated in interviews at the time that his days of watching the show had ended well before.)

In a 2011 YouTube video, made on the 40th anniversary of the original TV spot, Mr. Backer acknowledged that he was not solely responsible for the Coke ad but indicated that he was willing to at least share in the accolades it won, noting that it was “very good.”

Looking up from the keyboard of a piano, on which he accompanied himself as he sang the words, he explained the message of the commercial, the perfect harmony of warm feelings with the product being advertised.

What it achieved, he said, was to remind viewers that the product could in some small way serve as a “social catalyst,” uniting people whose differences in nationality, race and physical appearance were merely superficial.

“Sometimes,” he said, “communications get better if you’re just sitting over a bottle of Coke and looking people in the eye.”

According to a history of the ad on the Coca-Cola website, Mr. Backer, then creative director on the company’s account, was flying to London to meet part of a team that would write radio commercials to be recorded by a British singing group, the New Seekers.

Forced to spend time at the airport in Shannon, Ireland, waiting for fog to lift, Mr. Backer saw some of his fellow passengers shift in mood, from grumpiness to joviality, as they told of their travels over snacks, coffee, tea and bottles of Coke. They were an international crowd, as the flight was bound for London, then Germany and then to the Far East.

Just then, Mr. Backer saw the familiar product of sugary soda water in a new light, with the invitation to have a Coke a “subtle way of saying, ‘Let’s keep each other company for a little while.’ ”

Inspiration struck immediately, he told Newsweek. “Right there, I wrote it on an envelope . . .‘I’d like to buy the world a Coke and keep it company.’ ”

One member of the songwriting team in London, Billy Davis, was initially underwhelmed at the idea.

“Well, if I could do something for everybody in the world,” Davis said, according to the Coca-Cola company history, “it would not be to buy them a Coke. . . . I’d buy everyone a home first and share with them in peace and love.”

“Let’s write that,” Mr. Backer replied, “and I’ll show you how Coke fits right into the concept.”

Playing off a jingle they initially called “Mom, True Love, and Apple Pie,” the songwriters crafted the ultimate lyrics that began:

I’d like to buy the world a home

And furnish it with love

Grow apple trees and honeybees

And snow-white turtledoves

The song — by then retitled “I’d Like to Buy the World a Coke” — was not received well at Coca-Cola headquarters in Atlanta until many DJs began reporting that the commercial jingle was one of the most requested tunes from listeners. Mr. Backer then greenlighted a TV advertisement, working with a creative team that visualized young people on a hillside, harmonizing.

It was initially going to be filmed on the English cliffs of Dover, featuring hundreds of British schoolchildren. But after extensive rain delays, the crew relocated to sun-dappled Rome. The first woman in the short was, according to Coke, a “young lady on vacation in Rome from Mauritius.”

The budget ran to $250,000 — a whopping figure at the time — and Davis later produced a pop record version with the song, amending the title to “I’d Like to Teach the World to Sing (in Perfect Harmony).” From there, it ascended the charts and brought Mr. Backer a lifetime of renown.

William Montague Backer was born in Manhattan on June 9, 1926, and moved to his mother’s home town of Charleston, S.C., in 1932 after the death of his father.

He graduated in 1944 from Episcopal High School in Alexandria, Va., then served in the Navy for two years before earning an undergraduate degree from Yale University in 1950. After trying his hand at selling real estate and writing freelance advertising jingles, he joined McCann Erickson, a major Madison Avenue firm, as a mailroom trainee in 1953. He worked over the years on the Coke, Buick and Exxon accounts for McCann, rising to vice chairman and creative director before resigning in 1979 over a dispute with the parent company.

Mr. Backer then started Backer & Spielvogel with a McCann colleague, Carl Spielvogel, bringing with them the $85 million Miller beer account. The company — which had a reputation as one of the best run, fastest growing in the country — was purchased in 1986 by Saatchi & Saatchi, which later merged it with Ted Bates Worldwide, providing a financial windfall for the founders.

Mr. Backer was later inducted into the American Advertising Federation’s Advertising Hall of Fame. Survivors include his wife 33 years, of the family farm near The Plains, Va.