Just out of curiousity, how do you know that? Seriously, I'm not being flip. Did they make any diary entries or send any letters that you still have that indicate why they were fighting? Did they tell someone this after the war and it has been handed down by word of mouth? I've got two gggrandfathers that fought, one in the Missouri State Guard and one in the 14th Arkansas, but I have no idea why they were fighting - their reasons were not passed down and they left no written record, so all I can do is speculate.