What are some similarities and differences between the American Civil War and World War II?

The other
answers cover many of the similarities and differences between the wars very well. One chief
similarity I would emphasize, however, is that both wars were fundamentally about clashes of
opposing ideologies. This is a contrast to other American wars, such as the
French and Indian War or World War I, which were primarily about land acquisition and power
politics, fought between nations that adhered to similar worldviews.

The
Civil War, in contrast, arose out of a dispute about the proper way to organize society: should
it be organized according to strict racial and gender hierarchies that included the ownership of
one group by another, or should slavery and excessive hierarchy be outlawed in favor of a more
equal opportunity society? These two ideological visions became so incompatible that the
Southern ruling class felt it had to break away from the United States to preserve its way of
life. The result was the defeat of the South and the abolition of slavery, but also
the...