I think it created a kind of illustration of how far our society's laws might go before they become overly weighty.  We now know that prohibiting alcohol isn't the best answer for a number of reasons, even if the spirit of the law had some good things attached to it.  So it does still affect us in our psyche which acknowledges that some laws can be too broad.  I don't think that the 18th Amendment was “damaging” to America, at least in any permanent sense.

I watched a history on cocaine recently and it's interesting to see how it got started.  It began as a “miracle drug” which was added to a lot of different products.  Only after some time did it dawn on people that it was addictive and led to destructive behavior.  I think that this is the kind of sentiment that alcohol had as well.  If I recall correctly cocaine was restricted by states and only later by the federal government, perhaps in the 1920s (but maybe earlier).  This would coincide with the timing of the 18th Amendment.  I don't know why something like alcohol would be de-criminalized but drugs would not be, other than if they realized that alcohol wasn't as addictive and it could still be enjoyed in moderation.  It would be interesting to see the correlation in governmental timing in its response to both alcohol and cocaine (and other drugs).

Alcohol in moderation is not a bad thing and some of it has even been shown to have health benefits (red wine) but I cant see things like Cocaine and Meth having any kind of health benefits just because of the addictive nature.

That is the key; one is fine in moderation, another is not.  This is my question about the pro-marijuana movement as well; a glass of wine won't necessarily make you unfit to drive a car, but a joint will.

Well, I don't think that comparing alcohol to drugs is ridiculous, but merely that some distinctions should be made between the two.  Based on my understanding, alcohol was taking its grip on people of the early 20th Century and it especially became hurtful to married women and families.  In a day where messages of moderation might not have been heard, or where the culture of drunkeness more prevalent, you can see how the effect of alcohol could have felt like a scourge to American society.  It may have been the case where Prohibition had an effect of changing the culture to one of more moderation between 1920 and 1933 (though I do not know this to be fact).  Today our culture has become one where moderation is key.  There are still those who drink to excess (e.g. colleges) but I think that your mainstream customer of wine does not buy wine to drink excessively.  Furthermore, I think we've probably become more sensitive to crimes such as drunk driving, so this has probably decreased. 

I think that touches on an issue which affects us even today.  How much responsibility do we place on the human individual's decision to partake in evil and how much do we place on the object which helps to facilitate evil?  It's the same issue with guns; some want gun control to prevent crime, others want to control criminals to prevent crime.  Because alcohol is addictive, I can see how Carrie Nation and others could have found this to be the end against which their crusade was aimed.  As I've stated in another thread, cocaine was discovered to have a very detrimental and addictive effect on people in the early 20th Century.  Other drugs probably underwent the same scrutiny around this time.  It's important to take all of this into account when we ask why alcohol was prohibited.  If we consider that liquor was outlawed in a vacuum it might seem odd, but if we consider that it was prohibited along with cocaine, perhaps heroin, opium, etc, all of which were seen to have had a demonstrably evil effect on Americans and their family life, it's a different story.  It then took some time for the public to separate the evils of drugs from the evils of alcohol and to realize they weren't quite equivalent.

Not commonly known is the fact that there was a monetary motivation for the 18th amendment.  John D. Rockefeller gave over $30,000 to the Woman's Christian Temperance Union (http://www.rockarch.org/collections/family/jdrsr/cc/sumwyz.php) which in today's dollars would probably be over $15,000,000 to help fight for prohibition, not temperance.  He may have believed in the cause, but he also stood quite a bit to gain because with alcohol out of the way, the fuel for the new boom of motor cars would become gasoline, which was produced by Rockefeller's Standard Oil monopoly.