While Christopher Columbus and his crew of explorers were not the first Europeans to set foot on land in the western hemisphere (i.e., temporary Norse timber colonies of Leifsbudir and Straumsfjord circa 1000CE, in Newfoundland and Nova Scotia, Canada), they were the first such explorers to be heralded for their "discovery" of new lands to the west. The Viking explorations centuries earlier were accomplished by seafaring peoples with no written language or histories, so the knowledge of such North American settlements was lost until recent archaeological excavations and the so-called Vinland documents. Nevertheless, it is Christopher Columbus and his crew who are remembered as being the first Europeans to discover the new world. This discovery brought with it rapid colonization by the western European powers (namely, England, France, Spain, Portugal and the Netherlands), new trade commodities, advances in seafaring and supply preservation, and new contacts between cultures. Unfortunately, Columbus' discovery of the new world is also shrouded by the violence and death directly and indirectly inflicted on peoples indigenous to the western hemisphere.
Christopher Columbus' discovery undoubtedly changed history by opening up new lands for the European imperial powers to colonize and conquer, signaling the end of western hemisphere civilizations that were pushed to extinction or collapse, introducing products such as corn, potatoes, tobacco and chocolate to the rest of the world, and by laying the foundations for the new states of the western hemisphere.
The "discovery" of the New World by Christopher Columbus changed the history of the world completely. This is not to say that Columbus himself was that important -- he was just the first European to reach the New World in circumstances that allowed for major colonization to happen. So it was not the "discovery" that mattered so much as the colonization.
Columbus's "discovery" allowed the period of colonization to begin. This had a number of important effects. From our perspective as Americans, the eventual creation of the US is probably the most important of these effects. By "finding" the New World, Columbus started its European colonization. This eventually ended up allowing the US to be created. The creation of the US helped, among other things, to move much of the world towards democracy. It also led to the development of what is now the world's only superpower.
A world without the United States is impossible to imagine today. The existence of the US was made possible by the "discovery" of America and that is, therefore, one of the ways in which Columbus's discovery changed history.
History was primarily changed by the exchange of plants and animals between Europe and the Americas, commonly known as the Columbian Exchange. Tomatoes, Potatoes, and Corn (Maize) previously unknown in Europe became an important part of the diet of people living there. Similarly, Cattle, Sheep, and Hogs were introduced into the Americas. Sadly disease was also introduced and had a devastating effect on both societies. Entire groups of people were wiped out in the Americas by smallpox, measles, etc. while in Europe an epidemic of Syphilis, previously unknown there, took a terrible toll.
Some truly high points and low points of Columbus's voyages and discoveries. As with everything there is good and bad. I'm going to mention a ripple from these discoveries. As pohnpei mentioned, these voyages allowed for the colonization of America. From an egocentric stand, this was good for many of us. We cannot forget, however, the ripple effect this had on the indigenous people of the US. The travesties and slaughter committed against massive populations of America'sindigenous people can be attributed to Columbus's discoveries which lead to American colonization.
It has also allowed for the euro-centric view of the world to be propagated upon millions of students. The fact that we even use the term "discovery" with Christopher Columbus as opposed to colonization or some other more applicable term. The use of "discovery" implies that no one knew about it, clearly the millions of people inhabiting the new world didn't think he discovered it...
But this view of history and perspective used to look at history has had great effects on the way we view the world and the way we act in it.
If you look at the fact that many Europeans felt that there was nothing beyond Europe and that the world itself was flat, I would say that the discovery of a new world by Columbus had a huge impact on Europe at that time. As mentioned above it opened up the world of trade and also was the beginning of the Age of Exploration.
actually you guys are wrong because he never set foot on american soil
He also set about the Columbian Exchange, whereby the indigenious people got stuff like potatoes, while the Europeans got meat. Also, the Columbian Exchange caused the death of many indigenous people in the form of diseases like smallpox, which the indigenous people had no resistance against.
It also brought about Columbus Day, where people celebrate Columbus' discovery. However, some people, more often than not indigenous people, denounce the holiday. According to a press statement released by the American Indian Movement, Colubus Day is when people "celebrate with holiday parades and festivals the invasion of our sacred lands by the colonial pirate Christopher Columbus". This shows that Columbus did change history.