The right of revolution is an inherent one. When people are oppressed by their government, it is a natural right they enjoy to relieve themselves of oppression, if they are strong enough, whether by withdrawal from it, or by overthrowing it and substituting a government more acceptable.
I never was an Abolitionest, not even what could be called anti slavery, but I try to judge farely and honestly and it become patent to my mind early in the rebellion that the North and South could never live at peace with each other except as one nation, and that without Slavery.
Ulysses S. Grant (1822 - 1885)
Source: Letter to Elihu B. Washburne, August 30, 1863
The issue of slavery provoked little moral indignation in General Grant, and in the first days following the attack on Fort Sumter, he seems to have believed that the North shared his indifference to abolition: "In all this I can but see the doom of Slavery. The North do not want, nor will they want, to interfere with the institution. But they will refuse for all time to give it protection unless the South shall return soon to their allegiance, and then too this disturbance will give such an impetus to the production of their staple, cotton, in other parts of the world that they can never recover the controll of the market again for that comodity. This will reduce the value of negroes so much that they will never be worth fighting over again."