Thaddeus Stevens (1792 – 1868, image) was one of the most powerful members of the United States House of Representatives. Stevens and Senator Charles Sumner were the prime leaders of the Radical Republicans during the American Civil War and Reconstruction.
The Radical Republicans were an ardent anti-slavery faction of the then-fledgling Republican Party.
A bit of a rogue, Thaddeus Stevens loved wild gambling, daredevil horseback riding, and his mulatto housekeeper, Lydia Smith.
Regarding Abraham Lincoln’s first Secretary of War, Simon Cameron, Lincoln asked Stevens, “You don’t mean to say you think Cameron would steal?” To this, Stevens replied, “No, I don’t think he would steal a red-hot stove.”
Cameron later heard about the remark and was furious. He demanded a retraction. Stevens considered, then told Lincoln, “Well, he is very mad and made me promise to retract. I will now do so. I believe I told you he would not steal a red-hot stove. I now take that back.” 
In the 1830s, when the Anti-Masonic party had begun morphing into the Whig party, Stevens was a steadfast holdout to Anti-Masonry. In the 1830s, “he sought the passage in the [Pennsylvania] Legislature of a resolution of inquiry into the desirability of making membership in the [Masonic] order cause for peremptory challenge in court, when one and not both principals in a suit were Masons.” 
Later, Stevens “succeeded in securing a legislative inquiry into the ‘evils’ of the order.” 
“Carrying his fight to the finish, he spoke in Hagerstown, Maryland, on the proposition that ‘wherever the genius of liberty has set a people free, the first object of their solicitude should be the destruction of Free Masonry.'” 
But by the 1840s, Stevens’ public ardor against Masonry had been channeled into “radical” anti-slavery. Was he influenced by his not-so-secret lover, the mulatto Lydia Smith?
Abraham Lincoln, like Thaddeus Stevens, belonged to the Republican Party. Unlike Stevens though, Lincoln was not a “radical” abolitionist.
In a talk given to the Oshkosh Education Association in 1938, Otto Eisenschiml “revealed that, in his opinion, [Abraham] Lincoln was murdered and [William] Seward attacked because they were friendly to the southern states, to the extent of receiving them back into national affairs with equal representation and full powers as individual states.” The South had not in fact legally seceded (since secession was not permitted), believed Lincoln. The Civil War in his view had only been a time of “strained relations.” (Background: Who Was Otto Eisenschiml?, Ersjdamoo’s Blog, July 15, 2015.)
If Lincoln had not been murdered, the South likely would have been received back into the Union with equal representation and full powers as individual states. This in turn would have impeded the freeing of the slaves, enacted by the 13th Amendment, ratified by “the required number of states” on December 6, 1865. Among these “required number of states” were the ex-confederate states of Virginia and Louisiana, where ratifications were submitted by Reconstruction governments. “These, along with subsequent ratifications from Arkansas and Tennessee raised the issues of how many seceded states had legally valid legislatures.” 
“Reconstruction governments” involve the “Reconstruction Era” (1865 – 1877), when the South was under military occupation. So you can see that the assassination of Abraham Lincoln on April 14, 1865 had consequences for the later enactment of the 13th Amendment on December 6, 1865. If Lincoln had not been killed, the South, likely received back into the Union with equal representation and full powers as individual states, might not have ratified the 13th Amendment as they did under the Reconstruction governments.
Even so early as 1929, wrote Claude Gernade Bowers, “few realize how intensely Lincoln was hated by the Radicals at the time of his death.”  And so it was that Thaddeus Stevens, leader of the “Radical” faction of the Republican Party, “warmed into life the brutal instincts of [Edwin] Stanton, [Joseph] Holt and [Lafayette] Baker, to have Lincoln assassinated.” 
Perhaps Thaddeus Stevens convinced himself that the homicide would be justified because by killing Lincoln an immense number of slaves would gain their freedom. “The end justifies the means,” Stevens may have told himself.
But what Stevens did not reckon with were unforeseen consequences which followed from the Lincoln assassination. That, in other words, is called “blowback”: unintended consequences of a covert operation that are suffered by the aggressor.  A possible example of “blowback” is in the news today: “Gunman Kills 4 Marines at Military Site in Chattanooga”, reports the New York Times. A 24-year-old Kuwaiti-born gunman is said to have “killed four United States Marines, prompting a federal domestic terrorism investigation.”  Was it blowback? The United States has been killing people with drone aircraft, supposed to have “pinpoint accuracy” but in truth innocent persons are murdered due to “collateral damage.” So the reported attack by the Kuwaiti-born gunman which killed the four Marines in Chattanooga might be sort of “instant karma”, i.e., blowback.
What was the blowback for the intra-Republican Party coup d’état of April 14, 1865, when President Abraham Lincoln was shot and mortally wounded? “The voice of thy brother’s blood crieth unto me from the ground.” (Genesis 4: 10). Unforeseen ramifications of the 1865 homicide are planned to be explored in future entries of this blog.
——- Sources ——-
 What Would Millard Do?, by Brian Francis Redman. Published by Lulu.com, 2009.
 “Thirteenth Amendment to the United States Constitution”, Wikipedia, July 17, 2015.
 The Tragic Era: The Revolution after Lincoln, by Claude G. Bowers. Cambridge, MA: The Riverside Press, 1929.
 Addenda to the Addenda, Ersjdamoo’s Blog, July 14, 2015. https://ersjdamoo.wordpress.com/2015/07/14/addenda-to-the-addenda/
 “Blowback (intelligence)”, Wikipedia, July 17, 2015.
 “Gunman Kills 4 Marines at Military Site in Chattanooga”, by Richard Fausset, Alan Blinder and Michael S. Schmidt. New York Times (online), July 16, 2015.