The answer here would be Aristarchus. He presented the first known Solar System model that showed the sun as being the center of the universe with the earth revolving it. He was also the first one to show that the Earth rotated on an axis.
The New World crops that added the most calories to European diets and therefore positively impacted sustainable population numbers were "<span>b. Potatoes and maize," since these were the most abundant and had the most nutritional benefits. </span>
There were many reasons. For starters, it involved getting rid of a large number of Native Americans, and while some supported this, others opposed it as they were peaceful. Another thing was that this meant the introduction of new states and it deepened the division based on whether the states should be slave states or non-slave states. Also they involved war with Mexico and some wanted this and some didn't.