Answer:
The Zhou created the Mandate of Heaven: the idea that there could be only one legitimate ruler of China at a time, and that this ruler had the blessing of the gods. They used this Mandate to justify their overthrow of the Shang, and their subsequent rule.
I believe it has to do with corruption with foreign policy.
The U.S didn't want war but rather Texas which was part of the Mexican empire at the time wanted a secession from the empire and join the U.S but was denied privilege to Independence, So the U.S sent troops to the area to sort with the tension to diplomatically solve this but got attacked with casualties. The rest is history
I hope I was a help to you
