The major consequences of bringing the Americas into contact affect environment and society of American, such as Columbian exchange, trade, and plants. And sub-Saharan Africa effect of the slave trade were massive, in term of demographic and caused wars which brought about additional death, as well as environment destruction because of European demand and greed increased. In the 14th century, Columbian exchange is often remembering for positive things that brought foods and plant between old and new world. But there also was colonies exchange of disease, plant, livestock, animal, and people. Diseases were transferred from European to American which people suffered immensely from the disease that were new to them, such as smallpox, measles, malaria, etc. with large number of disease brought to the new world, the Indian population was immensely impacted by these illnesses. The Indian population was devastated by the illness, since Indian were isolated from other cultures and people before the arrival of European. Since the disease was extremely communicable, the spread of the disease was rapid. This made the Indian to become infected easily which wipe had of the population. Once humans domesticated these animal, the disease quickly jumped to human. But native American did not have many domesticated animal and thus germs and antibodies did not coevolve here and they never developed resistance. Spreading disease was the only one way that trade affected American society and