ProgressingAmerica: The Chicago Historical Society found no reason to discount the material, so the word unreliable is inappropriate.
There is a JSTOR article that directly addresses the papers of the Leman family referenced by MacNaul's 1915 paper: "A Mighty Contest'': The Jefferson-Lemen Compact Reevaluated — James. A Erdstrom, Journal of the Illinois State Historical Society (1998-), Vol. 97, No. 3 (Autumn, 2004), pp. 192-215 (24 pages)
Here are some choice quotes from the paper (bold and underline are emphasis mine):
"Given the significant, even radical, implications of the story of the Jefferson-Lemen Compact, it is difficult to understand why MacNaul made no thorough effort to verify the authenticity of the relevant documents. Even if those original materials had "gone the way of all paper" and were no longer available, it is hard to believe there would be no other documents to support the story - in the Thomas Jefferson papers, for example. As it was, MacNaul chose merely to present the Lemen family papers as published without inquiring too closely as to their provenance and without attempting to find any corroborating evidence in other archival collections. Indeed, in the years since MacNaul's publication, there has been no systematic effort to evaluate either the documents or the story they narrate."
"This much is clear about the Lemen family papers: there are a total of thirteen documents comprising the collection, and of these, eight are directly relevant to the story of the Jefferson-Lemen Compact. Of these eight, six are definitely fraudulent and the remaining two are skeptical."
The paper then goes on to describe in detail why the various papers are fraudulent by contradicting them with other publicly available letters and evidence. With regards to Jefferson, we have this section which seems relevant:
"The fifth document is a letter from Thomas Jefferson to Robert Lemen (brother of James Lemen Sr.) dated 10 September 1807. As earlier mentioned, John Mason Peck quotes only a fragment of this letter in his alleged history of the compact. In it, the third President wrote of his regard for James Lemen Sr. and asked Robert Lemen to urge his brother to visit Jefferson. There are several problems with the provenance of this document. Jefferson was a meticulous correspondent, carefully preserving the letters he received and copying those that he sent. There is no record of this letter in any of the sources consulted, and, for that matter, no reference to any correspondence or contact between Jefferson and James Lemen Sr. Jefferson wrote letters on 8 September and 19 September, but none on 10 September 1807. Jefferson was traveling between Monticello and Bedford, Virginia, during the period of 9-17 September, which would not have been conducive to maintaining his usual painstaking correspondence habits."
"The next document, the alleged diary of James Lemen Sr., is in many ways the most problematical of all the Lemen family papers. The author of this diary penned it in a very self-important, self-aware style, almost as if the author is consciously composing it for the audience of posterity. It moves erratically from brief references to Lemen's family to detailed descriptions of his political and religious activities, and overall it lacks the authentic voice found in pioneer letters such as those written by Gershom Flagg, who settled in Madison County in 1818. Moreover, there are clues within the diary that detract from its validity. For example, on 28 December 1785 Lemen recorded that Jefferson's confidential agent gave him one hundred dollars "of his funds to use for my family, if need be, and if not to go to good causes, and I will go to Illinois on his mission next Spring and take my wife and children." A careful examination of Jefferson's account book for the time period covering 2 May 1784, when Jefferson and Lemen supposedly met, through 31 December 1785 reveals no transaction corresponding with this incident."
"Ultimately, the central difficulty of establishing the validity of the story of the Jefferson-Lemen Compact lies in the complete lack of provenance for the Lemen family papers. No one, certainly not Joseph Lemen, who was more responsible than anyone for attempting to popularize the story, ever produced the original documents themselves or validated copies. There are several notations from James Lemen Jr. within the diary as published by Willard MacNaul: "I have examined the within notes and find them to be true copies of notes kept by Rev. James Lemen, Sr., which were fading out."59 In other words, he had undertaken the rigorous task of comparing transcriptions of the diary entries with the originals. However, these, too, are questionable due to the date of attestation: 4 June 1867. Lyman Copeland Draper, who corresponded with Lemen Jr. in the course of Draper's research on early Midwestern history, recorded that, during the summer of 1868 (only one year after the attestation date), he called upon Lemen Jr. and found that "his memory had all faded out, so he could give no information whatever." Moreover, in his correspondence with Draper a few years earlier, James Lemen Jr. made repeated references to his inability to provide substantial assistance to Draper's research owing to his own feeble health. In this context, it is questionable whether Lemen Jr. would have been capable of such extensive copy editing."
Even contemporary reactions to Macnaul's 1915 paper were clear as to the fact that such a compact relied upon the authenticity of the Lemen papers, and that the lack of being able to authenticate them was problematic. "Moreover, if the original papers were as valuable as Joseph Lemen suggested, there should be at least a record of them somewhere, even if the papers themselves have disappeared. By rights, some provision should have been made for their retention and preservation. The examination of the wills of both James Lemen Jr. and Joseph Lemen, written in 1870 and 1906, respectively, reveals no reference to the Lemen family papers."
Overall, despite the Lemen-Jefferson's position in popular history, "Scholars who have studied the life and career of Thomas Jefferson likewise call the story of the compact into serious question. Merrill D. Peterson wrote in 1960 that in spite of initial support from some historians, "the best authorities on the Old Northwest have for some time regarded it as false or unproven." He also noted that Julian Boyd, editor of the Jefferson papers, had found no record of any relationship between Lemen and the third President. Boyd himself commented directly upon the issue to author Lyn Allison Yeager in 1975 by saying "The so-called 'Jefferson-Lemen Compact' is without foundation ... that such a compact existed is inherently implausible and, with respect to Jefferson, wholly uncharacteristic."...Why Joseph Lemen chose to put forth questionable - indeed, fraudulent - documents in the service of a spurious story is at best a matter for speculation. As shown, Lemen was ardently anti-slavery and it seems unnecessary for Joseph Lemen to perpetuate a rumor linking James Lemen Sr. and Thomas Jefferson in a conspiracy to outlaw slavery in Illinois. The history of the Lemen family's service in the antislavery cause is documented and unimpeachable, and their legacy merits respect and admiration. In the face of the evidence and the doubtful validity of the Lemen family papers, however, the story of the Jefferson-Lemen Compact must ultimately be consigned to the realm of myth."
All told, in spite of the claims of the original post, I don't think this alleged compact is worth boasting about, at least insofar as it concerns Thomas Jefferson.
This JSTOR article makes much more sense, thank you for providing it, as well as the many paragraphs of in-depth analysis which was not provided earlier.
For me, at least, this new information clears things up about this set of documents and story line.
FWIW, when I searched for this after seeing it appear the only JSTOR article that I saw was much shorter. The one you provided I cannot read at all except for the first page, so I trust in good faith that your cut and pastes are accurate to the remaining pages of
XIII. ABRAHAM LINCOLN'S LETTER
Belleville Weekly Advocate, April 24, 1908The following letter and remarks from Abraham Lincoln, hitherto unpublishhed, comprise the fifth letter of the series of old "Pioneer Letters" which Mr. J. B. Lemen of O'Fallon is sending to the Advocate.—Ed.
Springfield, Illinois. March 2, 1857.
Rev. James Lemen,[O'Fallon, Illinois,]
Friend Lemen: Thanking you for your warm appreciation of my views in a former letter as to the importance in many features of your collection of old family notes and papers, I will add a few words more as to Elijah P. Lovejoy's case. His letters among your old family notes were of more interest to me than even those of Thomas Jefferson, written to your father. Of course they [the latter] were exceedingly important as a part of the history of the "Jefferson-Lemen Anti-Slavery Pact," under which your father. Rev. James Lemen, Sr., as Jefferson's anti-slavery agent in Illinois, founded his anti-slavery churches, among which was the present Bethel church, which set in motion the forces which finally made Illinois a free state, all of which was splendid; but Lovejoy's tragic death for freedom in every sense marked his sad ending as the most important single event that ever happened in the new world.
Both your father and Lovejoy were pioneer leaders in the cause of freedom, and it has always been difficult for me to see why your father, who was a resolute, uncompromising, and aggressive leader, who boldly proclaimed his purpose to make both the territory and the state free, never aroused nor encountered any of that mob violence which both in St. Louis and Alton confronted or pursued Lovejoy, and which finally doomed him to a felon's death and a martyr's crown. Perhaps the two cases are a little parallel with those of John and Peter. John was bold and fearless at the scene of the Crucifixion, standing near the cross receiving the Savior's request to care for his mother, but was not annoyed; while Peter, whose disposition to shrink from public view, seemed to catch the attention of members of the mob on every hand, until finally to throw public attention off, he denied his master with an oath; though later the grand old apostle redeemed himself grandly, and like Lovejoy, died a martyr to his faith. Of course, there was no similarity between Peter's treachery at the Temple and Lovejoy's splendid courage when the pitiless mob were closing around him. But in the cases of the two apostles at the scene mentioned, John was more prominent or loyal in his presence and attention to the Great Master than Peter was, but the latter seemed to catch the attention of the mob; and as Lovejoy, one of the most inoffensive of men, for merely printing a small paper, devoted to the freedom of the body and mind of man, was pursued to his death; while his older comrade in the cause of freedom. Rev. James Lemen, Sr., who boldly and aggressively proclaimed his purpose to make both the territory and the state free, was never molested a moment by the minions of violence. The madness and pitiless determination with which the mob steadily pursued Lovejoy to his doom, marks it as one of the most unreasoning and unreasonable in all time, except that which doomed the Savior to the cross.
If ever you should come to Springfield again, do not fail to call. The memory of our many "evening sittings" here and elsewhere, as we called them, suggests many a pleasant hour, both pleasant and helpful.
Truly yours,
A. Lincoln.
The Collected Works of Abraham Lincoln, Vol. 8, pg. 452, Appendix 2:
Mar. 2 to James Lemen, forgery, Tracy, 71.
The letter was rejected for the Collected Works of Abraham Lincoln due to it being a forgery. That is the Collected Works of 1953. Seventy one years later the progressives are recycling this fictional creation published in 1915.