Final answer:
The main cause of the American Civil War was the question of whether slavery should be allowed in new territories.
Step-by-step explanation:
The main cause of the American Civil War was the question of whether slavery should be allowed in new territories.
This issue had been a source of conflict between the North and the South for many years, as the North opposed the expansion of slavery while the South wanted to protect and expand their slave-holding economy.
Other factors, such as the development of industry and manufacturing in the North, added to the tensions between the two regions, but the question of slavery was the primary cause.
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