A page from Dixon's "Clansman"

Thomas Dixon jr. was a lawyer, state legislator, preacher, novelist, playwright, actor, lecturer, real-estate speculator, and movie producer. He wrote a Ku Klux Klan trilogy, of which "The Clansman" (1905, freely downloadable from numerous providers) gained notoriety through Griffith's film classic "The birth of a Nation" (1915). In the novel, Lincoln is described as a noble and generous man, as opposed to "Austin Stoneman", the novel alias of Thaddeus Stevens. We quote the sole page, from the chapter Triumph in defeat, where Dixon lets Stoneman utter his inner beliefs.  

It's a fine and early example of the use of violence and injustice to improve people and beat them into a better world.

The doctor, who was walking back and forth with his hands folded behind him, paused and said: "I marvel that a man of your personal integrity could conceive such a measure [the Confiscation Act]; you, who refused to accept the legal release of your debts until the last farthing was paid—you, whose cruelty of the lip is hideous, and yet beneath it so gentle a personality, I've seen the pages in the House stand at your back and mimic you while speaking, secure in the smile with which you turned to greet their fun. And yet you press this crime upon a brave and generous foe?"
        "A wrong can have no rights," said Stoneman, calmly. "Slavery will not be dead until the landed aristocracy on which it rested is destroyed. I am not cruel or unjust. I am but fulfilling the largest vision of universal democracy that ever stirred the soul of man—a democracy that shall know neither rich nor poor, bond nor free, white nor black. If I use the wild pulse-beat of the rage of millions, it is only a means to an end—this grander vision of the soul."
        "Then why not begin at home this vision, and give the stricken South a moment to rise?"
        "No. The North is impervious to change, rich, proud, and unscathed by war. The South is in chaos and cannot resist. It is but the justice and wisdom of Heaven that the Negro shall rule the land of his bondage. It is the only solution of the race problem. Lincoln's contention that we could not live half white and half black is sound at the core. When we proclaim equality, social, political, and economic for the Negro, we mean always to enforce it in the South. The Negro will never be treated as an equal in the North. We are simply a set of cold- blooded liars on that subject, and always have been. To the Yankee the very physical touch of a Negro is pollution."
        "Then you don't believe this twaddle about equality?" asked the doctor.
        "Yes and no. Mankind in the large is a herd of mercenary gudgeons or fools. As a lawyer in Pennsylvania I have defended fifty murderers on trial for their lives. Forty-nine of them were guilty. All these I succeeded in acquitting. One of them was innocent. This one they hung. Can a man keep his face straight in such a world? Could Negro blood degrade such stock? Might not an ape improve it? I preach equality as a poet and seer who sees a vision beyond the rim of the horizon of to-day." 
        The old man's eyes shone with the set stare of a fanatic.
        "And you think the South is ready for this wild vision?"
        "Not ready, but helpless to resist. As a cold-blooded scientific experiment, I mean to give the Black Man one turn at the Wheel of Life. It is an act of just retribution. Besides, in my plans I need his vote; and that settles it."