[pvg]

The time to reach that level of consensus for lots of things is longer than 70 years - it can easily be infinite. It's not really clear why the final date in your timeline is 1998 since it doesn't mark a time when 'all the machinery in play effectively came to the conclusion'. The dangers of smoking tobacco were widely known through much of the period you've picked and this is also reflected in your timeline.

[daenz]

From the article, 1998 was the year that the Tobacco Institute and the Committee for Tobacco Research disbanded, which I am perceiving as symbolic of the last formal resistance to the idea that smoking causes cancer.

[pvg]

Sure but it's a pretty arbitrary cutoff. Many other significant limits on smoking (workplace bans, indoor bans, airlines, etc) and various limits on tobacco advertising happened both earlier and later. Some big tobacco lawsuits happened later. Just about any doctor in the 70s, 80s or 90s would have told you smoking is bad for you, public perception and knowledge of the dangers changed over time, etc, etc, etc. The whole thing doesn't really fit in a neatly bracketed time period in a meaningful way.

[civilized]

The tobacco lawsuits of the 90s brought the episode to a close. Tobacco companies now have to admit the health harms of smoking. Philip Morris does so at the top of marlboro.com and in several other places.