McClellan on the Civil war - June 1864 at West Point

Stripped of all sophistry and side issues, the direct cause of the war, as it presented itself to the honest and patriotic citizens of the North, was simply this: Certain States, or rather, a portion of the inhabitants of certain States, feared, or professed to fear, that injury would result to rights and property from the elevation of a particular party to power. Although the Constitution and the actual condition of the Government provided them with a peaceable and sure protection against the apprehended evil, they prepared to seek security in the destruction of the Government, which could protect them, and in the use of force against the national troops holding the national forts. To efface the insult offered to our flag; to secure ourselves from the fate of the divided republics of Italy and South America; to preserve our Government from destruction; to enforce its just power and laws; to maintain our very existence as a nation -- these were the causes which impelled us to draw the sword. 
Rebellion against a government like ours, which contains the means of self-adjustment, and a pacific remedy for evils, should never be confounded with a revolution against despotic power, which refuses redress of wrongs. Such a rebellion cannot be justified upon ethical grounds, and the only alternatives for our choice are its suppression, or the destruction of our nationality. At such a time as this, and in such a struggle, political partizanship should be merged in a true and brave patriotism, which thinks only of the good of the whole country. It was in this cause and with these motives that so many of our comrades have given their lives, and to this we are all personally pledged in all honor and fidelity.
Shall such devotion as that of our dead comrades be of no avail? Shall it be said in after ages that we lacked the vigor to complete the work thus begun? That after all these noble lives freely given we hesitated, and failed to keep straight on until our land was saved? Forbid it heaven, and give us firmer, truer hearts than that...It must be the intention of the overruling Deity that his land, so long the asylum of the oppressed, the refuge of civil and religious liberty, shall again stand forth in bright relief, united, purified and chastened by our trials as an example and encouragement for those who desire the progress of the human race. It is not given to our weak intellects to understand the steps of Providence as they occur; we comprehend them only as we look back upon them in the far-distant Past. 
So is it now. We cannot unravel the seemingly tangled skein of the purposes of the Creator -- they are too high and far-reaching for our limited minds. But all history and His own revealed word teach us that his ways, although inscrutable, are ever righteous. Let us then honestly and manfully play our part; seek to understand and perform our whole duty; and trust unwaveringly in the beneficent God who led our ancestors across the sea, and sustained them afterward, amid dangers more appalling even than those encountered by His own chosen people in their great exodus. He did not bring us here in vain, nor has he supported us thus far for naught. If we do our duty and trust in Him, He will not desert us in our need; firm in our faith that God will save our country, we now dedicate this site to the memory of brave men, to loyalty, patriotism and honor.