You seem to have overlooked the fact that he was an abolitionist. He was not justifying slavery, he was condemning the Constitution, which he soured on because it did NOT abolish slavery.
A word of warning ... don't try to portray Spooner as a defender of southern slavery on any forum where Spooner's positions are more well known -- you will be seen as a laughable baffoon.
Not in the least, and in fact I have made note of that at every opportunity as it gives moral credibility to his position. It speaks volumes that an extreme abolitionist such as Spooner would speak out against the manner in which Lincoln's war was conducted. It also shows that simply noting the evil by which Lincoln conducted that war and its big government consequences does not automatically make someone a "slavery-defending racist bigot white male homophobe rain forest strip miner", as certain persons here like to imply. Here is what he had to say on the matter in a letter to Charles Sumner from 1864:
"You have thus, to the extent of your ability, placed the North wholly in the wrong, and the South wholly in the right. And the effect of these false positions in which the North and the South have respectively been placed, not only with your consent, but, in part, by your exertions, has been to fill the land with blood."
He was not justifying slavery, he was condemning the Constitution, which he soured on because it did NOT abolish slavery.
No. He was condemning the actions that led to the establishment of the authoritarian post-war government. Of the pre-war government, he held out at least theoretical tolerance of its existence. Here is what he said on that issue and how the war changed it:
"Previous to the war, there were some grounds for saying that --- in theory, at least, if not in practice --- our government was a free one; that it rested on consent. But nothing of that kind can be said now, if the principle on which the war was carried on by the North, is irrevocably established...Notwithstanding all the proclamations we have made to mankind, within the last ninety years, that our government rests on consent, and that that was the rightful basis on which any government could rest, the late war has practically demonstrated that our government rests upon force --- as much so as any government that ever existed."