CHICAGO (AdAge.com) -- U.S. cigarette advertising has largely faded into the background in recent years amid growing restrictions on tobacco advertising and a shrinking market. Cigarette ad spending has fallen 95% from its 1985 peak, according to the most recently available Federal Trade Commission report. U.S. cigarette consumption has tumbled 42% since its 1981 peak.

But tobacco marketing was a big deal to Madison Avenue in the 20th century. Consider this: Tobacco companies accounted for seven of the nation's 100 largest advertisers in 1964, the year that the Surgeon General issued his game-changing report on smoking and health.

Just what occurred over the decades in the smoke-filled rooms of cigarette marketers and agencies was largely a secret. Now, however, outsiders can get a glimpse of the inside through a vast pool of internal documents available for public view.

The Legacy Tobacco Documents Library has amassed 11.4 million tobacco industry documents from the late 1800s to the present, with the bulk of the material from 1950 through 2002. The documents became available mainly through lawsuits brought by states that resulted in the 1998 Master Settlement Agreement between major cigarette marketers and states.

The library is housed at the University of California, San Francisco, and is supported by the American Legacy Foundation, an anti-smoking organization.

Advertising Age's 80th anniversary report, "80 Years of Ideas," includes three major tobacco-related events. Below is a sampling of library documents related to those events.

Industry hires Hill & Knowlton, 1953

Research and press coverage in the early 1950s were drawing a link between smoking and cancer. Reader's Digest's damning 1952 story: "Cancer by the Carton."

Cigarette industry response? It rolled out filter cigarettes, which many consumers perceived to be safer than nonfilter smokes. And the industry created a PR smokescreen: Cigarette makers hired Hill & Knowlton and formed the Tobacco Industry Research Committee, initially housed in the public relations agency's office.

A December 1953 report prepared for the industry stated: "It is important that the public recognize the existence of weighty scientific views which hold there is no proof that cigarette smoking is a cause of lung cancer."

The committee in January 1954 ran a newspaper ad disputing "a theory that cigarette smoking is in some way linked with lung cancer." The ad states: "We believe the products we make are not injurious to health."

Hill & Knowlton worked for the committee until 1964, when the committee changed its name to Council for Tobacco Research-USA; seven Hill & Knowlton employees at that point joined the council as staffers.

The PR agency continued on the tobacco industry's payroll for decades to come. In 1990, for example, Hill & Knowlton provided the Tobacco Institute, a now-defunct trade group, with a list of "high-profile" smokers from "entertainment/news," government, "athletics/arts" and business.

Philip Morris and Leo Burnett introduce Marlboro, 1955

Philip Morris hired adman Leo Burnett in November 1954 to relaunch Marlboro in 1955. Philip Morris had marketed Marlboro since 1924 as a "luxury" nonfilter cigarette; Burnett felt it had a "sissy" image, what he called "a fancy smoke for dudes and women."

He detailed his plans in a letter to the client: "The job of Marlboro advertising is to take a new popular-priced filter cigarette with an old luxury cigarette name and give it a personality and a reason for being that will make it stand out among all the brands in a chaotic and fast-growing field."

Mr. Burnett noted filter cigarette sales had tripled "in a year marked by widespread publicity on the possible harmful effects of cigarette smoking." His letter continued: "Right here is where you run into a temptation to go off half-cocked. You say to yourself: `Hmmm, people are afraid smoking cigarettes may harm them. Then all we have to do is tell them that our filter makes cigarette smoking safe and we can lean back and watch the money roll in.'"

The agency executive cautioned against that positioning, writing: "We have a pretty strong hunch that the psychologists know what they're talking about when they tell us that people who have `fears' resent being reminded of those `fears.'"

Burnett advised Philip Morris to focus on the flavor of Marlboro, with secondary emphasis that it comes in an innovative "crush-proof box" and that "it's a long-size cigarette at the popular filter price."

Research found that smokers considered all filter cigarettes "slightly effeminate," so Burnett's plan was for Marlboro ads to show only men, all "carefully selected to appeal to both sexes."

The first ads featured cowboys. "The cowboy," Burnett told his client, "is an almost universal symbol of admired masculinity." Other early Marlboro ads showed masculine "regular guys."

Philip Morris in 1962 settled on the cowboy as the exclusive image of what Burnett called the Marlboro Man. In 1963, the cowboy was given a home: "Marlboro Country."

Marlboro went on to become the nation's and world's No. 1 selling cigarette. Philip Morris has billed Marlboro as "the world's best selling packaged good and most valuable brand across any product category."

The last Marlboro cigarette magazine ad seen in the U.S. ran in 2005, but Marlboro continues to be advertised abroad. Burnett still works on the brand.

Surgeon General's 1964 report; Hill & Knowlton's market research

The Surgeon General's 1964 Report on Smoking and Health made it official: Smoking may be hazardous to your health.

And so began tobacco's decades-long decline. Cigarette per-capita consumption peaked in 1963, the eve of the January 1964 report.

In 1965, Congress passed the Cigarette Labeling & Advertising Act, requiring tobacco firms to put health warnings on cigarette packs. Major airlines in 1967 stopped passing out cigarettes during flights. Cigarette broadcast advertising was banned in 1971.

Cigarette consumption has tumbled 42% since its 1981 peak. Cigarette ad spending -- $51 million in 2006, according to the most recently available Federal Trade Commission report -- has plunged 95% from its 1985 peak ($932 million).

Back in 1964, tobacco companies accounted for seven of the nation's 100 largest advertisers. In 2006, for the first time, not a single tobacco company appeared in Ad Age's ranking of the top 100 ad spenders.

In March 1964, Hill & Knowlton had a market research study prepared to analyze consumer reaction to the Surgeon General's report.