Answer:Since the French decided to join the American side as an ally during the American Revolutionary War, they send a bunch of resources, man power(aka soldiers) and more to help their side (they also send Lafayette). Due to all of this, the Americans failed to pay back the debt to France in a short period of time(because their country just started and they need to organize everything), causing French to need to raise the taxes on the common people in their land, making life hard (because they need to feed mouths and their wages aren’t high) and forcing them to start a revolution (poor king that helped the Americans, he got his head chopped up for it).
There are more reasons but this is all I can think of for now.
Slavery. north wanted one country. south wanted to become separate nation
To defend off the invasions from northern invaders, Emperor Qin Shi Huang had all the walls joined up. Thus, the Great Wall came into being
