Despite the fact it never receives a response because it is, I suspect - too logical and non-controversial to start a thread of its own, and for the benefit of the newer posters who have not seen my response to these questions, I will post my "standard" reply to "Why they fought" and "Why they seceded" since it is similar to what you just said, Ken.
It is this - It all depends on who you were - a northern shipbuilder, a Southern plantation owner, a northern politician, a Southern politician, a Southern rural farmer, a northern industrialist, a Southern industrialist, a northern slave, a Southern slave, a northern farmer, any of the above with relatives in the north or the South, and on and on, i.e., there wsa no single reason. I would even go so far as to say there is no majority reason - there were many reasons and, hence, many anwswers to these questions.
Let's see if this gets any response this time?