Grass: History of Marijuana is a 1999 Canadian documentary film directed by Ron Mann, premiered at the Toronto International Film Festival, about the history of the United States government's war on marijuana in the 20th century.
Grass: A Documentary on the War on Marijuana is a 1999 Canadian documentary film directed by Ron Mann, which was first screened at the Toronto International Film Festival and examines the US government's battle against marijuana in the 20th century.