Obviously tobacco had been around for god knows how long and other cultures may have been using it for various medicinal purposes and even smoking it for a very long time when the European explorer set out to discover the new world and all the amazing things across the Atlantic. But up until this point in time it was not indigenous to Europe at all (that most historians are aware of) and it certainly wasn't used.
So to say he discovered tobacco is a little misleading because it has always existed and used by people for a long time but his scribblings in his journals on this day were the first time that Western society has any sort of reference to what has become one of the most widespread agricultural goods in the world.
The year was 1492
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I've always loved this image because Columbus was just like "ok, we are here now so that means that this land is ours"
Columbus and his accomplices were given the tobacco by natives in great quantities but when they tried to eat it or cook it the results were not very pleasant. They actually threw a bunch of it away but then noticed that the locals would roll it up and start it on fire and then inhale the smoke. This would make the natives sleepy and a few of Columbus' crew members started doing the same. One of the most famous members of the crew that became addicted to smoking (a practice that i'm told still happens to people today) was Rodrigo de Jerez. When Rodrigo de Jerez took this practice back to Spain in the hopes of making some fame and fortune off of the product he got half of it right. Spain was a very religious and paranoid part of the planet at the time and he was put into prison because obviously if you can blow smoke out of your mouth and nose you are working with Satan in some capacity. OBVIOUSLY!
Today, despite near global efforts to curb tobacco use, the industry is worth more than a trillion dollars annually and anytime that something is worth that much you can rest assured that the government's propositions and directives are probably more for public relations than they are for actual concern for you and your welfare. Money does drive everything after all, even politics (as hard as that is to believe)
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the page of Columbus' journal containing the tobacco reference
There are a lot of things that ol' Christopher is credited with discovering that he didn't actually discover, such as North America, It is generally believed that he never actually set foot on the continent (although he did get close) and in regards to tobacco as well as other sorts of plants he didn't really discover them so much as he introduced them to Europe.
Major parts of the rest of the world probably already had and used these things they just weren't a "thing" in Europe yet. Europe being by far the most militarily powerful place on the planet at the time in terms of technology gave them a tremendous advantage as far as claiming to be the "first" at just about anything at the time.
For me, I was addicted to smoking for nearly 25 years and was a habit that wasn't frowned upon even for teenagers when I had my first ciggy at the ripe young age of just 15 or so. I stopped smoking a few years ago and have no intention of ever turning back and have seen massive improvements to my health in just a general sense ever since. If you are a smoker you already know that what you are doing is going to have a massive impact on your future health and I am not here to lecture you about this.... you already know.
But anyway, the western world became first aware of smoking tobacco (or smoking anything at all) due to notes that were scribbled down by the most famous explorer of all time on this day, a mere 528 years ago.