Why does the United States want all the drugs that make you feel really good to be illegal?

With the only exception is alcohol. Why does the US continue this war on drugs instead of making them legal for personal use? Why are some drugs legal while others are not? Does it have anything to do with safety? Why is this making kids try all kinds of crazy things to get high such as, cough syrup, jenkem, the choking game, huffing gasoline, prescription pills. Someone told me they people who do those things to get high so they wont get in trouble with the law are a victim of the war on drugs in a way. If prohibition on alcohol didnt work, why is it working for everything else? Did certain drugs become illegal have anything to do with safety?