In 1944, 41% of U.S. adults said they smoked; this figure held steady for the next several decades, even after the federal government warned the public in the early 1960s that smoking was a health threat.

At the start of the 1970s, four in 10 Americans still reported smoking, but by 1977, the rate had fallen to 36%. Twelve years later, in 1989, the smoking rate fell below the 30% mark for the first time. However, over the next two decades the smoking rate was relatively stable with about a quarter of Americans saying they smoked.