Lincoln's letter to her was printed by the Boston Evening Transcript and reprinted widely thereafter. However, later it was revealed that only two of Mrs. Bixby's five sons died in battle (Charles and Oliver). One deserted the army, one was honorably discharged, and another deserted or died a prisoner of war.
In addition, the authorship of the letter has been debated by scholars, some of whom believe that it was written instead by John Hay, one of Lincoln's secretaries. The original letter, unfortunately, has been lost.
Dear Madam,
I have been shown in the files of the War Department a statement of the Adjutant General of Massachusetts that you are the mother of five sons who have died gloriously on the field of battle.
I feel how weak and fruitless must be any word of mine which should attempt to beguile you from the grief of a loss so overwhelming. But I cannot refrain from tendering you the consolation that may be found in the thanks of the Republic they died to save.
I pray that our Heavenly Father may assuage the anguish of your bereavement, and leave you only the cherished memory of the loved and lost, and the solemn pride that must be yours to have laid so costly a sacrifice upon the altar of freedom.
Yours, very sincerely and respectfully,
A. Lincoln