Thaddeus Stevens called President Andrew Johnson (image) the “offspring of assassination.” Johnson, the Vice President, became President after Abraham Lincoln was assassinated. President Johnson therefore was the “offspring” of Lincoln’s assassination. But who were the parents and grandparents of the offspring?
An 1868 editorial in The People’s Weekly, a now rare magazine, accused the vindictive fury of Thaddeus Stevens of having given life to the embryo spirit of assassination in Edwin Stanton and Joseph Holt. Thaddeus Stevens was the grandparent of assassination. Edwin Stanton and Joseph Holt were the parents. John Wilkes Booth pulled the trigger. And President Andrew Johnson was the offspring, sprung from the dying Lincoln. (Background: Addenda to the Addenda, Ersjdamoo’s Blog, July 14, 2015.)
On February 22, 1866, in a speech given from the White House steps to an assembled crowd, President Andrew Johnson spoke of “the man who has assassination brooding in his bosom.” Enemies of Johnson considered him to be an “obstacle” which “must be gotten out of the way”, for Andrew Johnson tried to adhere to what he believed Abraham Lincoln would have wanted, and the Radical Republican faction which had been the parents and grandparents of the Lincoln assassination had other plans. “Whether by assassination or not,” Johnson told the crowd, “there are individuals in this Government, I doubt not, who want to destroy our institutions and change the character of the Government. Are they not satisfied with the blood which has been shed? Does not the murder of Lincoln appease the vengeance and wrath of the opponents of this Government? Are they still unslaked? Do they still want more blood? Have they not got honor and courage enough to attain their object otherwise than by the hands of the assassin?” 
It is apparent that Johnson was implying “the ‘c’ word” in the above. Was Andrew Johnson a “conspiracy theorist”?
Andrew Johnson had been born in a log cabin. In his youth, he worked as an apprentice tailor. Through the tutelage of his wife, Eliza, he learned to read. Like Abraham Lincoln, Andrew Johnson was mostly self-educated. 
At his tailor shop, Johnson began to host political discussions. From this he became interested enough to make visits to a local college where he “matched wits” with the students there. His political life acquired its own momentum, and Johnson rose eventually to become U.S. Senator from Tennessee. 
At the time of the secession of the southern states, Johnson, a Unionist, was the only southern senator not to resign from office. His explanation for this decision was, “Damn the negroes, I am fighting those traitorous aristocrats, their masters.” 
This gives an idea of the backbone of the man: all southern senators, except the lone Andrew Johnson, essentially went over to the Confederate side. Johnson was known for his at times fierce temper. At such moments of excitement, a soft “Andrew, Andrew,” from his wife always calmed Johnson down instantly.  His fiery temperament though gave Andrew Johnson the courage to resist the coup d’état forces behind the Lincoln assassination.
A member of the House of Representatives from Pennsylvania, Thaddeus “Old Thad” Stevens, was chief of the Radical Republican forces. On December 13, 1865, Congress created the Joint Committee on Reconstruction. It consisted of nine representatives and six senators, most of them Radicals hand-picked by Stevens. President Johnson called the Joint Committee the “French Directory,” a reference to the dictatorship by committee that emerged during the French Revolution. 
Under Stevens’ leadership, Congress passed a reconstruction law, described at the time as “written with a steel pen made out of a bayonet.” The law abolished all Southern state governments set up under Johnson’s previous program. In their place, Congress created five military districts, each commanded by an army officer. The army commanders were authorized to rule by martial law, using federal troops and military courts to maintain order. President Johnson vetoed the law, saying that it would create an “absolute despotism” over the South. But Congress voted to override his veto. 
And thus began the odious Reconstruction. Johnson suggested it amounted to another rebellion, this time from within, following hard upon the overt War of Rebellion. “[W]e find ourselves almost in the midst of another rebellion,” said Johnson to the people gathered outside the White House. “The war to suppress our rebellion was to prevent the separation of the States, and thereby change the character of the Government and weakening its power. Now, what is the change? There is an attempt to concentrate the power of the Government in the hands of a few, and thereby bring about a consolidation, which is equally dangerous and objectionable with separation. We find that powers are assumed and attempted to be exercised of a most extraordinary character. What are they? We find that Government can be revolutionized, can be changed without going into the battle-field. Sometimes revolutions the most disastrous to the people are effected without shedding blood. The substance of our Government may be taken away, leaving only the form and shadow.” 
——- Sources ——-
 “Speech to the Citizens of Washington”, Andrew Johnson, February 22, 1866. http://teachingamericanhistory.org/library/document/speech-to-the-citizens-of-washington/
 The Tragic Era: The Revolution after Lincoln, by Claude G. Bowers. Cambridge, MA: The Riverside Press, 1929.
 “Andrew Johnson”, Wikipedia, October 17, 2009.
 “King Andy and the Radicals”, http://www.crf-usa.org/impeachment/impeachment-of-andrew-johnson.html