What are the roots of the American War of Independence and Civil War?

The reason of American War of Independence: resisting the endless oppression of British colonies and striving for independence.

Causes of the Civil War: Slavery seriously affected the development of American capitalism. The north needs free slaves to enter factories, while the south needs slaves to work in farmland. Lincoln won the election, which made the north stronger than the south. In order to protect themselves, the south began to rebel. In the final analysis, the cause of the civil war is the outbreak of violence after the collision of the two systems.