"When the enemy occupies high ground, do not confront him. If the enemy attacks from the high ground, do not oppose him." - Sun Tzu
Joshua Chamberlain won the Medal of Honor for ordering the charge from Little Round Top, one of the most famous actions of Gettysburg and the entire Civil War. John Buford is one of the great unsung heroes of the Union side. It was he who selected the field of battle at Gettysburg. It was his tenacity and tactical acumen that ensured the Union maintained the high ground outside the city.
Saying that the Civil War was about slavery is kind of like saying that the American Revolution was about taxes: it's true as far as it goes but it's so reductionist as to be misleading. The South seceded in order to preserve slavery which was integral to their economy. They inadvertently ensured that "United States" became a singular rather than the plural which it had been for the entire antebellum period. Before the war, the only contact most people had with the federal government was the post office. After the war, the states have gradually become merely convenient subdivisions of the federal government.
You can tell a lot about a person's politics by asking them when the United States started to go wrong. Mainstream conservatives and neocons, aka right-liberals, usually say either the Great Society or the New Deal. Paleocons blame the US entry into World War I or the Federal Reserve or the Union victory in the Civil War. Libertarians blame either the Union victory or the passage of the Constitution over the objections of the Anti-Federalists. Personally, I blame William of Ockham for everything.
Regardless, the 14th Amendment has been the vehicle used by progressives to transform the laws of the United States into enemies of God and nature, and to mutate the old Republic into the creaking multicultural empire it is today. It guarantees "equal protection of the laws," which strikes me as a meaningless abstraction. Laws against trespassing are not going to equally protect us at 123 Fake Street if you own a home there and I do not.
Studying American history has always been something of a melancholy experience. You can almost taste the boundless optimism of the Founding Fathers. You almost envy the early Republic where men took great interest in public affairs and vigorously discussed the issues in countless newspapers and public forums. Wherever you believe the decline began, it's all downhill from there, culminating in Obergefell.
When the United States breaks apart later this century, it's difficult to imagine it being as bloody an affair as the first Civil War. No matter who secedes or for what reason, a good number of whites will be thinking, "Good riddance." The Coalition of the Fringes might think otherwise, but I honestly don't believe our fabulous overlords have got the balls for a serious campaign of persecution involving red martyrs.