Final answer:
The US fought a civil war between 1861 and 1865 due to economic differences, disagreement over slavery expansion, and states' rights. The war aimed to preserve the Union and end slavery.
Step-by-step explanation:
The US fought a civil war between 1861 and 1865 due to several factors, including economic differences between the North and the South, disagreement over the expansion of slavery into new territories, and states' rights. These tensions culminated in the secession of Southern states and the formation of the Confederate States of America. The war was fought to preserve the Union and end slavery.
Learn more about Reasons for the American Civil War