That Remarkable Case
Five years later, a newspaper article about this incident – REMARKABLE CASE OF ARREST FOR MURDER – was submitted anonymously to the Quincy [IL] Whig “by a member of the Bar.” Ward Lamon, an associate’s of Lincoln, attributed the article to Lincoln in an 1872 biography, as have other Lincoln scholars. 
While the article is more clear and written with five years hindsight, I don’t find it nearly as interesting as this rendition in the letter. Plus, it undoubtedly underwent some editing for clarity’s sake; hence removing some of the spontaneity of Lincoln’s narrative. However, click the link above for your own comparison.
It’s peculiar that Lincoln revisits a case he won, and five years after the fact. That he does so in an anonymous fashion – less so – given that he represented one of the defendants. But even Lamon mentioned that Lincoln seemed discomforted with it all. 
Legal Lesson, Protest, or What?
The following editorial comment prefaced Lincoln’s “anonymous” article:
The following narrative has been handed us for publication by a member of the bar. There is no doubt of the truth of every fact stated; and the whole affair is of so extraordinary a character as to entitle it to publication, and commend it to the attention of those at present engaged in discussing reforms in criminal jurisprudence, and the abolition of capital punishment. ED. WHIG. 
The editor of the Whig saw the subject of Lincoln’s narrative worthy of the attention of those reforming the legal system and advocating ‘abolition of capital punishment.’ Perhaps. But Lincoln’s discomfort with this case was evident in his letter to Speed one day after it ended. Also, there appears no mention in any of the other Lincoln’s papers of his participation or even interest in the abolition of the death penalty.
However, Lincoln DID advocate making better and clearer laws as a member of the Illinois State Legislature. That motive may account for his discomfort with the way the Trailor case played out. But a five-year hiatus, during which time he IS a member of a law-making body? It doesn’t quite add up.
Two things the article DID provide however, which the letter did not; one was a curious epilogue and the other a legal speculation – without recommendations.
Here’s the epilogue.
Five years later,
William and Archibald have both died since—William in less than a year, and Archibald in about two years after the supposed murder. Henry is still living, but never speaks of the subject.
After noting there were ‘many curious speculations‘ about the facts of the case, Lincoln then added a recitation of the various legal ramifications of Fisher’s death for the Trailor brothers given several different scenarios.
It is not the object of the writer of this, to enter into the many curious speculations that might be indulged upon the facts of this narrative; yet he can scarcely forbear a remark upon what would, almost certainly have been the fate of William and Archibald, had Fisher not been found alive.
It seems he had wandered away in mental derangement, and, had he died in this condition, and his body been found in the vicinity, it is difficult to conceive what could have saved the Trailors from the consequence of having murdered him. Or, if he had died, and his body never found, the case against them, would have been quite as bad, for, although it is a principle of law that a conviction for murder shall not be had, unless the body of the deceased be discovered, it is to be remembered, that Henry testified he saw Fisher’s dead body. 
This legal review served as the end of Lincoln’s Whig article. It was interesting to note what might have happened if Dr. Gilmore had failed to act immediately or if Fisher hadn’t found his way to Gilmore’s. It certainly provides a lesson in how a person’s fate so often hangs on such a legal nuances.
However, to see this as the editor did – a tract for legal reform and a death penalty protest – is a stretch.
What about guilt? Was there something about his part in representing Arch Trailor that he felt wasn’t adequate or was it just his natural inclination toward tidiness – the “black/white not shades of gray” way Lincoln viewed the world?
It seems less the guilt trip [as Lincoln was only one of three defending attorneys] than it does his way of seeing the world. This case rocked Lincoln’s concrete view. The unique hastiness of the letter and the continued interest in the case five years after its conclusion all lend credence to a paradigm shift in his thinking/awareness. His world view was changed with that case. Perhaps the instant realization of the whims in our everyday existance that can lead to destruction – not the destruction of life and death, but a destruction of the path on which we’ve set our lives.
Then again, perhaps it’s just the fact that there were “holes” in the case that were never closed.
‘A Strange Affair’ – Other Theories or Educated Guesses
In two other references published years after the fact, each author endeavored to add his own unique speculation about the holes in the case.
The work most historians quote at some length is Roger W. Barrett’s. A Chicago lawyer, Barrett edited Lincoln’s mystery in a seventy-some page pamphlet in 1933 entitled A Strange Affair. In it, he provides a plausible explanation for nearly all of the unanswered questions in the case. A summary of these is found in the Annotations of “The Trailor Murder Case” document.
But he concludes as follows:
The real mystery of the case is why Archibald and William Trailor would never reveal what occurred, nor the circumstances under which they parted from Fisher, nor tell why, after leaving the searching party on the following day ostensibly to go to their homes, they again returned to the thicket and remained there for an hour or so while Henry stood guard. In the silence of the three brothers, these questions have remained unanswered for almost a century and there is no voice that can `provoke the silent dust’ to reveal their secret. [4&5]
The other author, Paul V. Ford, was also an attorney and former prosecutor whose hobby was writing about unusual legal cases. In the January 28, 1951 Grafic Magazine, a supplement to the Chicago Sunday Tribune, he wrote “The Crime That Baffled Lincoln.”
This article reiterates much of the Whig article, Lincoln’s letter, and Barrett’s supposition. However, he varies widely from all of them with what seems as some embellishment of the facts. He even introduces a “woman’s love” angle not previously offered.
Speculations abound. And we have ours.
However, this comment of Lincoln’s from his newspaper article provides the perfect ending for this weird and mysterious case, and it may contain the most revealing reason for his ongoing fascination:
Thus ended this strange affair; and while it is readily conceived that a writer of novels could bring a story to a more perfect climax, it may well be doubted, whether a stranger affair ever really occurred. 
‘…to a more perfect climax?’ Life isn’t that tidy is it?
Food for thought.
To read Part I or Part II of this weird case and the uncomfortable mystery just click below:
 “To Joshua Speed – June 14, 1841.” Collected Works of Abraham Lincoln. v.I:pp. 255-259.
 “The Trailor Murder Case – April 15, 1846.” Collected Works of Abraham Lincoln. v.1:pp.372-377.
 Lamon, Ward H. (1872). The Life of Abraham Lincoln from His Birth to His Inauguration as President. Boston, MA: James R. Osgood & Company. p. 317-321.
 “The Trailor Murder Case – April 15, 1846 – Annotations” Collected Works of Abraham Lincoln. v.1:p.377.
 Barrett, Roger W. (1933). A Strange Affair. No publisher available.
 Ford, Paul V. “The Crime That Baffled Lincoln – January 28, 1951.” Grafic Magazine, Chicago Sunday Tribune. p.9[?].