Europeans started to enslave Africans.
They started to use slaves instead of indentured servants, because the investment was better. Indentured servants only served for a few years, and then were granted freedom, while slaves were purchased and used for their entire lives. The investment of a slave was better than an indentured servant.
Aristarchus’ only extant treatise is “On the Sizes and Distances of the Sun and Moon.” In it he calculated the diameter of the Sun as about seven times the diameter of the Earth, thus estimating the Sun’s volume as about 300 times the volume of the Earth
<span>In Mesopotamia, plant domestication led to population growth; in Mesoamerica, it led to plant extinction. Mesopotamian agriculture depended on seasonal rains, while Mesoamerican agriculture depended on river valleys. The people of Mesopotamia domesticated corn, whereas those in Mesoamerica domesticated rice. Domestication of grains occurred about 5,000 years earlier in Mesopotamia than in Mesoamerica.</span>
"popular sovereignty" which really just allowed settlers of the territory to decide whether slavery would be banned within their new state's border. Causing many people to rebel including the KKK.<span />
