Before founding his agency that that served such blue-chip marketers as Procter & Gamble and Nestle, Mr. McGrath worked at Benton & Bowles. In 1969, he branched off to join legendary Volkswagen art director Helmut Krone and Gene Case at Case & Krone. The agency later became Jordan Case McGrath. A suite at the Plaza Hotel functioned as the agency's office in its early years, when it represented accounts such as beverage flavor Angostura bitters; politician Bob Wagner, who was New York City's mayor from 1954 to 1965; and Francis Sargent, governor of Massachusetts from 1969 to 1975.
Mr. McGrath was known to be outspoken. A 1970 Ad Age editorial was dedicated entirely to criticizing his dismissive comments on the brand management system. He told Ad Age in 1972 that a powerful visual idea was missing in 75% of ads, and the cigarette category was a disaster because ads for Newport, L&M and Winston completely lacked visual ideas. "It would make no difference what name you use in the ad," he said. "They're a shocking waste of large sums of money."
His outspoken comments didn't stop marketers from coming to Jordan Case McGrath, which soon moved on to larger offices and larger clients. These included P&G, Hasbro Toys, Chapstick, Bounty and Scrabble. By 1997, Jordan Case McGrath was the 17th largest advertising agency in the New York area in terms of office billings, according to Crain's New York Business. One of its legacies is the "Tum-ta-tum-tum-Tums" jingle for Tums antacids, a jingle still in play 30 years later.
In 1999, Mr. McGrath sold his agency to Havas, and the name was changed to Arnold McGrath Worldwide.
Mr. McGrath published a memoir in 2012 called "The Way It Was," in which he detailed the challenges and rewards of starting an ad agency from scratch, handling celebrity spokesmen, managing conflicts and winning accounts.
He led several advertising and philanthropic organizations. He was a former president of the American Association of American Advertising Agencies, and also served as president and trustee emeritus of the Cancer Research Institute. He was a founder and board member of the Women's Sports Foundation.
Mr. McGrath grew up in the Bronx. His first job was selling peanuts at Yankee Stadium, and he called it "the best job I ever had." He was also an enthusiastic golfer, dedicated to playing in Scotland every year for the last two decades of his life. As he grew older, Mr. McGrath was known to tell stories and jokes to his children and grandchildren in an Irish accent, an homage to his Irish parents who moved to the U.S. in 1930.