Abraham Lincoln and his wife Mary Todd Lincoln were hit very hard by the death of their son Willie to typhoid fever on February 20, 1862.
He was the second son of theirs to die after Eddie. Indeed they almost lost another son, Tad, to typhoid fever but fortunately he recovered.
We've mentioned one of the ways in which the event is recorded in collectibles: a brief but significant letter from the President thanking an unknown Mr Crock for the gift of two white rabbits to his youngest son soon after the event.
We can assume that the gift was intended to comfort the now sad and lonely child. The letter sold for $57,000 near the end of 2011.
Whilst that letter was one of Lincoln's shortest, a letter from his wife to a family friend shortly afterwards was long and explicit. Mary Todd Lincoln was responding to the death of one Mrs Reeves in a letter to her husband, Charles.
Although the relationship between the Lincolns and the Reeves is not well-documented, the auctioneer which is selling the letter believes that it concerns Hester Reeves, who taught the Lincoln boys in Springfield, Illinois. In parts of the letter it's clear how well the two deceased individuals knew one another.
Mary Todd Lincoln's four page letter is heartfelt:
"The sad intelligence of the death of your most excellent wife had reached me two or three weeks before I received your letter, and I have been so bowed down and broken hearted myself or I should have written you to express my deep sorrow in your heavy bereavement.
"Where Mrs. Reeves was known, there her goodness and influence was ever felt. She was one of the pure hearted beings of this world."
Less than three months had passed since Willie Lincoln's death, and it's clear that his mother's grief had subsided little.
"There was no lovelier boy, than ours, and none more precious or more dearly loved yet he has been called away and we are left to our desolations and agony.
"Our Beloved Willie dearly loved your wife and I know she equally as much attached to him - And I fully know and believe they are this day together rejoicing in the presence of their Saviour."
Included with the letter is a photograph of Willie Lincoln (Mary Lincoln says it 'doesn't do him justice') and the envelope bears Abraham Lincoln's autograph in the form of a free frank.
The extraordinary lot will sell in an online auction starting March 15 and ending March 22.