For over 4,000 years the cannabis plant marijuana has been used medicinally by a variety of cultures around the world. It was used as a medicine in the United States until 1937, when a new tax led to its use being discontinued. In 1972, marijuana was placed in Schedule I of the Controlled Substances Act. Marijuana is the common name for the hemp plant Cannabis sativa ("Medical Marijuana"). Hemp grows in tropical and temperate climates. The dried leaves, flowers, and stems of the plant have a long history of being used as medicines. It has been cultivated in different regions of the world over the centuries for its fiber to produce linen, rope, canvas and oil. It has also been used as a medicine to relieve symptoms of disease and as a euphoric to induce states of intoxication or euphoria. Throughout its long history, parts of the plant have been smoked, eaten, chewed, or prepared for its pharmacological effects on human biochemistry. Marijuana is a green or gray mixture of dried, ground flowers and leaves of the hemp plant. There are many different names for marijuana. Slang terms change rapidly in different countries. Most users roll loose marijuana into a cigarette (called a joint). The drug can also be used in a water pipe. The most commonly reported effects of smoked marijuana are a sense of well-being or euphoria and increased talkativeness and laughter, alternating with periods of introspective dreaming, followed by lethargy and drowsiness. THC is the chemical in marijuana that makes you feel high. The effect of marijuana on the user depends on the strength or potency of the THC it contains. Long-term studies of high school students and their drug use patterns show that very few young people use other drugs without first trying marijuana ("How does marijuana use affect your brain and body?") . Opinion on Marijuana in the 1970s was much more definitive than it is today. The approval of marijuana by 27 states, new medical studies, and its consequences for those convicted of using the world's most popular illicit drug are forcing the United States of America to reconsider its position on the issue ("Marijuana should it be legalized? Overall, the underlying argument about marijuana in this country is: Should marijuana continue to be prohibited to citizens based on its health effects, medicinal values, and costs to the country? The reasons why this topic is so important are great.