Image Maurice Lévy of Publicis, left, and John Wren of Omnicom. Credit... Francois Mori/Associated Press

To understand the inner workings of agency life, he studied David Ogilvy’s advertising bible, “Confessions of an Advertising Man,” and read newspaper stories from the era, including the advertising column in The New York Times. He also consulted friends who had worked in the industry.

Mr. Weiner said that he was a student of ad campaigns from the period and was particularly interested in the influence that TV commercials had. Mr. Weiner pointed to a 1961 Pepsi campaign that introduced the slogan “For those who think young.” It exemplified advertising’s influence in creating the phenomenon of youth-obsessed consumerism that remains so prevalent, he said. It also provided the framework for the first episode of the second season, during which executives at the fictional Sterling Cooper advertising agency argue about how best to cater to clients trying to appeal to the members of “the Pepsi generation,” who don’t drink coffee like their parents.

The more research Mr. Weiner did, he said, the more fascinated he became with not only with the ad campaigns but also with the business operations and the personalities driving them.

“There are egos battling it out, and it has nothing to do with the business,” Mr. Weiner said. “It is not just a factory that makes advertising.”