I flew from JFK to Heathrow in 1986 (don't recall the airline but assume it was either a major US carrier or British Airways) - I vividly remember the cabin being full of cigarette smoke. I suppose there must have been a nominal "section" but can't remember.
According to Wikipedia:
"After years of debate over health concerns, Congressional action in 1987 led to a ban on inflight smoking.
The U.S. ban on inflight smoking began with domestic flights of two hours or less in April 1988, extended to domestic flights of six hours or less in February 1990, and to all domestic and international flights in 2000."
I was just thinking that, holy cow. It's bad enough when a smoker sits down next to you on the bus. Imagine the guy next to you lighting up on a four hour flight. Holy shit.
According to Wikipedia:
"After years of debate over health concerns, Congressional action in 1987 led to a ban on inflight smoking.
The U.S. ban on inflight smoking began with domestic flights of two hours or less in April 1988, extended to domestic flights of six hours or less in February 1990, and to all domestic and international flights in 2000."
https://en.wikipedia.org/wiki/Inflight_smoking