The Ohio River, as the dividing line between<span> slave states, </span>south,<span> and free-soil states, </span>north.
feudalism is a system that was used in the middle ages where kings would give land to knights and nobles to manage, and peasants and serfs would work the land in exchange for food, shelter, and safety. this system caused wealth and power to be based on land, not based on money or influence. it also caused the peasants and serfs to be tied to the land that they worked on, which caused them to be safe and provided for but it didn't give them freedom to move up in social class. feudalism also caused a temporary decrease in trade in europe because manors (the land that the nobles managed) were self-sufficient, so they had no need to trade anymore. however it kept peasants safe and fed, which made it a good system for the time, but was ultimately a negative system.
Galileo revolutionized the field of astronomy through the destruction or rather debunking of the Ptolemaic concept of the universe. He also was the one who showed that there were multiple moons (4 to be exact) revolving around Jupiter and that there were sunspots. All of this dramatically changed astronomy in the future.
