Marijuana use among American youths and young adults increased substantially during the 1990s. This paper reviews that trend using data collected 1979-2003 by the National Survey on Drug Use and Health (NSDUH). The data suggest that the increase in marijuana use started first among persons age 12-20. Among 18-20 year-olds, the increase started earlier among whites and blacks than Hispanics, among males before females, and surprisingly in areas that are not part of an MSA as opposed to those with a population in excess of a million. Much of the increase in marijuana use could have been attributable to the growing popularity of blunts. Starting in 2000, the NSDUH explicitly asked youths age 12-17 (but not older respondents) about smoking blunts. Of the 9% of youths who reported past-30-day use of marijuana 2000-03, more than half reported smoking blunts. On the other hand, the data also indicate that blunts have not fully supplanted other ways that youths consume marijuana. Blunts were more common among youths that were black, older, male, and from metropolitan areas. Many blunt smokers reported they had not used marijuana, which suggests that they did not define smoking blunts as marijuana use. Even fewer reported that they had used cigars, suggesting they did not define smoking blunts as cigar use.