To my mind, there's 2 big reasons. First, there's the South's pre-war mobilization in the wake of the John Brown incident at Harper's Ferry; second, the unique character of the leaders at the top (specifically, Lincoln, Davis, and Lee). First, the John Brown raid at Harper's Ferry stirred up Southern resentment and slave insurrection paranoia to unprecedented levels in the South. Whereas before John Brown's raid, there was just a vague fear that the Yankees and their liberal politics would invade Southern culture, the raid put all of those fears in play. In other words, it convinced thousands of Southerners that Northern bullying and policy-making wasn't just a political issue, but a social one that needed to be met head-on, with "cold steel" (a hawkish phrase of the day). Thus, when the Civil War actually started, the North wasn't facing a hastily organized rabble, but rather a militia system that had over a year to prepare and proliferate. As a result, the US government wasn't able to just brush aside the rebellion like it had in the past (see The Whiskey Rebellion for more on this), for the Southern rebellion had developed into a transcontinental uprising that stretched from Texas to Florida to Virginia (and elsewhere). The North hadn't counted on this, or the Southern resolve to fight, and it led to, as writer Shelby Foote termed it, "a very bloody affair." This leads to our second point, the unique character of the leaders. The South had also underestimated the North: specifically, Lincoln's resolve to keep the Union together, and the man's stomach for violence. They also put far too much faith in foreign recognition, which never came. This attitude and outlook was a reflection on Jefferson Davis' personality, which in the political realm, was very decisive and inflexible. The man ruled like an autocrat, not a canny politician, and refused to compromise once he had made a decision. Davis also relied too heavily on his pre-formed opinions of leaders like Gen. Bragg, and this led to a lot of heartache for the Southern armies. So on the one side you had an intractable Lincoln who never once considered compromise on the issue of maintaining the Union in one piece, and on the other, you had Davis, who was no less determined to see the South get its independence. Neither man was ever shown to budge on the issue (at least in any recorded instance we know of), and each man started the war underestimating their opponent's desire and/or capacity to make war indefinitely to resolve the dispute. To complicate matters, you had Lee working military miracles in the east (which undoubtedly prolonged the war for the south), and many Northern generals bumbling early on (or getting tangled up in bureaucratic messes like Burnside with the pontoons at Fredericksburg), which also prolonged the war. It was a perfect storm of clashing personalities that, when looked at with some perspective, boggles the mind. Is this a simplified and quick answer, of course: there's much more to it. For example, there are a number of other smaller, more idiosyncratic factors like the wheat shortage in Europe during the 1860s, which put a premium on Northern crop imports in contrast to the traditionally robust cotton demand (a low priority when food staples were in such high demand). I hope this helps! EDIT To add a point about your question regarding total war, if anything, that policy expedited the end of the war, it didn't prolong it. Sherman's campaigns through Georgia and the Carolinas were effective at their aims (mainly, destroying the Southern wartime manufacturing and transportation infrastructure and crushing morale back home, which led to a lot of desertions). [Sources, Douglas Southall Freeman, 'Lee's Lieutenants, v. 1'; Bruce Catton, 'Glory Road'; James McPherson, 'Battle Cry of Freedom'; Shelby Foote, 'The Civil War, a Narrative, v. 1']