American Cancer Society's annual smoke-free day, first observed November 18, 1976
The Great American Smokeout, initiated by the American Cancer Society, is an annual event encouraging smokers to quit for a day, aiming for permanent cessation. First held nationwide on November 18, 1976, it has since been observed every third Thursday of November. This campaign has contributed to a dramatic decline in U.S. adult smoking prevalence from 37% in 1976 to under 12% today.