Civil War, researching family tree, why did Lincoln get so many of my kinfolk killed?

[RockIt]

The north could not tolerate the south's slavery, and the opening up of the west to possibly more slave states. They just couldn't reconcile the issue, and this dominated the conflicts of northern state hostility to the south and its dependence on high labor agriculture that dominated the south's economy.

 

[My flag my pride]

From what I have learned, 5 brothers fought for the north and 4 for the South, only 1 from each side lived to return home. I have their diaries and papers, why did Lincoln in his thirst for blood cause such a war to happen.