The practice of smoking marijuana, also known as cannabis, became widespread during the 1920s -- in response to the "great social experiment" of alcohol prohibition. In 1970, the U.S. Federal government categorized marijuana (active ingredient: delta-9-tetrahydrocannabinol, or THC) as a Schedule 1 Substance, labeling it an illegal drug with no medicinal value and a "high potential for abuse." As early as 1972, campaigns to legalize the drug began. A report published that year by the National Commission on Marijuana and Drug Abuse argued that "private production and consumption of marijuana should be made legal."

Legal or not, statistics show that marijuana is the third most popular recreational drug in America. According to researchers, over 50 percent of all people will use marijuana at some point in their lives. The marijuana advocacy group NORML reports that almost 80 million Americans admit having smoked marijuana, and 20 million Americans used marijuana during the past year.

Nine states -- Alaska, Arizona, California, Colorado, Hawaii, Maine, Nevada, Oregon, and Washington -- have legalized the use of marijuana for medical purposes. Many Americans believe the consequences of using two ubiquitous, legal drugs -- alcohol and nicotine -- are far graver than those presented by cannabis. But their opponents cite the social and medical ills associated with marijuana as proof that the drug should keep its Schedule 1 status. And so far, the Supreme Court has backed that assertion.

Both sides of the debate point to empirical and anecdotal evidence to support their positions. But as Chris Colin wrote in a Salon article, "If there's a single obstacle to the acceptance of the drug's medicinal virtue, it's that it's fun, too."

Think you know where you stand on this issue? During the course of this activity, we will ask you five more times: Should the U.S. federal government legalize marijuana? Based on your responses, we will argue the opposite points of view. Only your final vote will count toward the results of this poll.