From the late 1960s into the 1980s, marijuana "smoke-ins" were held by legalization advocates, antiwar protesters, and others in big cities nationwide. The Youth International Party (Yippies) organized an early smoke-in attended by 25,000 in Washington, D.C. on July 4, 1970, a anti-war counter to the nearby "Honor America Day" festivities with Billy Graham and Bob Hope. The annual July 4 Yippie smoke-in in Washington, D.C., became a counterculture tradition.

Seattle held what was billed as its first smoke-in, called "Marijuana Awareness Day," in Volunteer Park in June 1979. Around a thousand people attended the peaceful event, and local police took a "no-enforcement" approach. This hand-drawn poster advertises the smoke-in, at "high noon" in Volunteer Park on June 10, with historic and modern images of smokers, and a cannabis leaf.