There is seldom time to write about all the interesting science stories that come our way. So this year we are releasing a special series of Twelve Days of Christmas publications again this year, highlighting a story that has fallen through the cracks every day from December 25 to January 5. Today: Results of forensic analysis of letter from Abraham Lincoln pardoning American Civil War soldier confirms that the date April 14, 1865 has been tampered with and cannot be removed without damaging the document.
A document containing President Abraham Lincoln’s signed pardon for a Civil War soldier has been the source of much controversy since its discovery in 1998, after historians concluded that the date was likely changed to make the document more historically significant. A new analysis by scientists at the National Archives confirmed that the date was indeed tampered with (although the pardon is genuine), according to a november newspaper published in the journal Forensic Science International: Synergy. The authors also concluded that there was no way to restore the document to its original state without causing further damage.
Thomas lowry is a retired psychiatrist turned amateur historian specializing in military civil war records and the author of numerous civil war stories. In 1998, he and his wife Beverly were browsing through a mine of rarely studied courts martial at the National Archives, carefully indexing the documents. At the time, there were no security cameras in the room, and the archive staff knew and trusted the Lowry’s. The couple discovered some 570 documents bearing Lincoln’s signature.
Among these was the pardon of a Union Army Civil War soldier named Patrick Murphy, a soldier who had been court martialed for desertion and sentenced to death. Forgiveness is written perpendicularly in the left margin of a letter dated September 1, 1863, asking for a forgiveness for Murphy. Lincoln’s statement reads: “This man is pardoned and hereby ordered to be removed from office. It was signed “A. Lincoln”.
This is the date that made the document meaningful: April 14, 1865, meaning forgiveness was likely one of President Lincoln’s last official acts, as he was assassinated later that same day at Ford’s Theater. in Washington, DC. Forgiveness has been widely interpreted as evidence of historical tale on the compassionate nature of the president: that is, his last act was an act of mercy. The discovery made headlines and brought Lowry considerable fame.
After its discovery, the pardon Murphy was exhibited in the Rotunda of the Charters of Liberty in the National Archives building. But an archivist named Trevor Plante became suspicious of the document, noting that the ink on the “5” in “1865” was noticeably darker. It also looked like another number was written underneath. Next, Plante consulted a seminal collection of Lincoln’s writings from the 1950s. Forgiveness was there, but it was dated April 14, 1864, a year before Lincoln was assassinated by John Wilkes Booth. Obviously, the document had been modified between the 1950s and 1998 to make forgiveness more historically significant.
Investigators naturally turned to the man who made the discovery for more information. They started to match with Lowry in 2010. At first Lowry seemed cooperative, but when he learned of the nature of the investigation, he stopped contacting the Inspector General’s office, raising suspicion. The investigators therefore knocked on the historian’s door one morning in January 2011 for an interview.
Shortly after, the National Archives issued a statement that Lowry had confessed to changing the date of the pardon. Lowry confessed to bringing a fountain pen into the research room, along with some fade-resistant pigment ink, and changed the “4” from “1865” to “5”. Lowry could not be charged with any felony because the statute of limitations for tampering with government property had expired, but he was banned from the National Archives for life.
But there’s a twist: Lowry quickly recanted, saying he signed the confession under duress from National Archives investigators. He said investigators assured him it would never be made public and that he would not suffer any consequences. “I consider these recordings to be sacred” he told the Washington Post at the time. “It is quite unusual for me. I am a man of honor.” His wife suggested that a more likely culprit was a former Archives staff member. (The agency denied this allegation.)
Along with the issue of Lowry’s innocence or guilt, National Archives curators were keen to take a closer look at the altered document and whether the original date could be restored by removing the fake “5”. Plant told the Washington Post he was not optimistic, because “Lowry deliberately used ink which will last a very long time.” The ink appeared to be iron gall ink, consistent with the time.
The National Archives have a state-of-the-art heritage science laboratory, with expertise in a wide range of analytical techniques that have become popular in cultural forensic circles. In the case of Lincoln’s Grace, the team took a close look at the date and signature in visible and ultraviolet light, as well as with the help of XRF Analysis compare the elemental composition of ink.
An examination of the “1854” under magnification and reflective fiber optic lighting showed that the ink used to write the “5” was indeed different from the overall color compared to the other digits on the date. Additionally, “ink remnants from a scratched number can be seen below and next to the darker ‘5’, as well as on the paper,” the authors wrote.
Additional analysis under grazing light—A technique that accentuates hills and valleys in the paper texture — revealed abrasions on the paper under and around the “5” that were not seen anywhere else on the document. The team also determined that the paper around the “5” is thinner than anywhere else, and that ink residue from the scraped off “4” was stuck in the abraded paper fibers, clearly visible using transmitted light microscopy.
Next, the team looked at the reverse side of the document, as Gallic iron ink is known to penetrate the reverse side of the paper, allowing the image of the text to be seen on the reverse side of the sheet. They noted that the penetration of the “5” was noticeably more intense than for the other digits, which the authors attribute to “the darker, blacker ink being applied more strongly to the already thinned paper when the ink of the original ‘4’ has been crossed out. “
Finally, the National Archives team used non-invasive methods XRF Analysis to identify what elements were present in the ink. They found the expected presence of potassium and sulfur (common to ferrogallic inks) in the ink used in the “L” of Lincoln’s signature and the “8” in the date. They also found calcium, probably added to the paper as a filler during its manufacture.
They compared this ink to the ink used to write the “5” and found that the overall signals for iron, potassium, and sulfur were much higher for the latter. This is not because the “5” ink has a thicker application. The iron / sulfur and iron / potassium ratios are also not the same. “There is strong support that the ink was not written by Lincoln but in more recent times with a thicker application, after the original Lincoln ‘4’ was removed,” the authors concluded.
This analysis also confirmed Plante’s pessimism about the prospect of removing the forged “5”, thereby restoring forgiveness to its original state. “Any further intervention or attempt to remove the new ‘5’ could not be done selectively and would only further damage the original materials of the historic document,” the authors wrote.
DOI: Forensic Science International: Synergie, 2021. 10.1016 / j.fsisyn.2021.100210 (About DOIs).