Frank Conner's take on things...
The central thesis of this book is as follows. President Abraham Lincoln singlehandedly started the War of Northern Aggression; and despite the best efforts of the Radical Republicans in Congress, he retained full control over that war. He waged it to preserve his own political future, by conquering the Southern states and putting them back under the control of the Northern capitalists. He sold his war to the Northern public as a war to 'preserve the Union' (maintain the North's economic control over the South). And that is why the North fought the war.
The Radical Republicans in Congress locked in a power struggle with Lincoln,
sought desperately to change the focus of the war to abolition - the issue which they clearly owned and cynically espoused - as their means for taking control of the war and the ensuing "peace". Their strategy for winning the hearts and minds of the
Northern public was a series of hate-propaganda campaigns against the white South.
It took them until a few months before the end of the war to convert a sizeable enough
segment of Northern opinion to their viewpoint so they could force Lincoln to react favorably to their demands.
So at the very tag end of the war, to the North's goal of 'preserving the Union'
was added the secondary goal of 'freeing the slaves' - for the most corrupt of reasons.
To claim - as the liberals and the black activists do today - that the North fought the war to free the slaves is sheer baseless propaganda.
The USA had fought and won its war of aggression against the
CSA. Might had made right. But now the US government needed to justify that war in the eyes of its own citizenry and the rest of the world, so it could claim a moral as well as a military victory.
Ex-president Jefferson Davis was captured by Union forces on May 10, 1865.
Andrew Johnson and his men were delighted by this turn of events. They believed that the most logical means of justifying the North's war would be to have the Federal government convict Davis of Treason against the United States. Such a conviction must presuppose that the Confederate states could not have seceded from the Union; so convicting Davis would validate the war and make it morally legitimate.
(And a judicial finding that the Southern states had never left the Union would
also strengthen President Johnson's claim that the president - and not the Congress -
now had jurisdiction over the Southern states).
Republican leader Thaddeus Stevens - who hated the Southern leaders virulently - nevertheless did not want Davis to be tried and hanged as a traitor, because the Southern states would fall under the jurisdiction of the Congress only if they were considered to be conquered parts of a nation which had seceded from the U.S.
And so Stevens announced, " The belligerent character of the Southern states was recognized by the United States.... the Southern states should be treated as a conquered alien enemy, and appropriated to the payment of the national debt. This can be done without violence to the established principles only on the theory that the Southern states were severed from the Union and were an independent government defacto, and an alien enemy to be dealt with according to the laws of war. Absurd to think of trying the leaders for treason.... No reform can be affected in the Southern states if they never left the Union... But by treating them as an outside conquered people, they can be refused admission to the Union unless they voluntarily do what we demand".
Stevens and the other radical leaders in Congress simply did not care that they were admitting that the Southern states had seceded Constitutionally from the Union and that the US had in fact waged a totally-unconstitutional war of aggression against another country - if such an admission were what it would take to bring the Southern states under the direct administration of Congress. The Congress wanted
that additional patronage and those additional votes and the additional taxation.
So in this matter, the executive branch was strictly on its own.
Initially, it seemed to President Johnson and his cabinet that everything was working in their favor. The Treason trial would be conducted in Virginia by Chief Justice Salmon P. Chase of the Supreme Court.
The War Department presented its evidence for a treason trial against Davis to a famed jurist Francis Lieber for his analysis. Lieber pronounced, "Davis will not be found guilty and we shall stand there completely beaten."
Attorney general Speed was badly demoralized by the events.
The United States of America would then stand exposed as having waged a war of conquest against its neighbor - purely for reasons of economic gain.
Attorney Speed decided he would need his own superlawyer to counter Davis'
superlawyer, Charles O'Conner (who was working pro bono for Davis). (He appointed John J. Clifford, but he said he had "grave doubts" about it).
Speed appointed another famed attorney to prosecute Davis, Richard Henry Dana... But Dana withdrew from the case. He said in effect that the North had won a military victory over the South, and the North should be content with that.
In 1866, President Johnson appointed a new US attorney general , Henry Stanburg. But Stanburg wouldn't touch the case, either. Thus had spoken the North's best and brightest re the legitimacy of the War of Northern Aggression.
Even though the Jefferson Davis case offered blinding fame to the prosecutor who could prove that the South seceded unconstitutionally.
And so the US government concluded that it did not have a leg to stand on; and that it would be seriously humiliated if it failed to prove during a high profile trial
of Jefferson Davis that the Southern states had not seceded lawfully from the Union. Nonetheless, the US government had to have its federal judiciary's official stamp of approval upon the war, to afford it the necessary justification; so in 1869, Chief Justice Chase chose a quiet, obscure case, TEXAS VS WHITE, in which to declare arbitrarily that secession had been unconstitutional, and therefore Texas, (and the other Southern states) had never left the Union.
Excerpts taken from Pages 187-192 THE SOUTH UNDER SIEGE - 1830-2000 by Frank Conner