It was a bloodbath. More Americans were killed in it than any war since. Nearly more than all other American wars combined. (I looked it up now....not the most reputable source though)
American Civil War: 620,000
American War of Independence: 4,500
War of 1812: 2,300
Mexican War: 13,300
Indian Wars:1,000
Spanish-American War: 2,500 (This seems a bit low to me. Probably doesn't count the pacification of the Philippines)
World War 1: 116,500
World War 2: 405,400
Korean War: 54,200
Vietnam War: 90,200
Gulf War: 2,000
War on Terror: 6,500
Total: 698,400
Getting back to the point, the American Civil War killed 620,000/31,000,000 people, or about 2% of the population. Taiping Rebellion killed 20,000,000/420,000,000 people, or about 4.7% of the population. But over the course of the history of the American Republic, China has had *4-5* such wars or massive population losses, only counting internal conflict. We can look at England pre-Parliament and post-Parliament and see, or any other country. The point I'm trying to get at is that democratic government is more stable long term, and perhaps it's worth having a messy decade or two if that goal is achieved. I stress *if*