Abraham Lincoln winning the President contributed most to the Civil War. After he won the election, southerners were scared that Lincoln would try to get rid of slavery and change their traditions. Once Abe Lincoln was elected, states started to secede (like South Carolina) from the Union just a couple months later. This secession ultimately lead to the confrontation at Fort Sumter, leading to the start of the Civil War.
White expansion. War between Indians and the whites was very common because the whites seemingly had quite an appetite for the Indian land. Indians struggle to contain this aggressive expansion led to war with hope to reduce American settlement and expansion.
True the Greek and Roman Empire were the foundation