It is now estimated $ 300K for sale by Stack's Bowers in Baltimore on October 25, lot 3002. It has meanwhile been graded Choice Fine 25 by PCGS.
I narrated it as follows in 2014.
The Civil War has begun and the Union will have to pay their soldiers. The government does not want to drain the Treasury of its gold and silver reserves and chooses the risky process of issuing a federal paper currency. 86 years before, the Continental currency had been a success to finance the war effort and a total failure for investors.
The Acts of Congress of July 17, 1861 and August 5, 1861 authorize the release of $ 250 million by the Treasury, including 60 million in bills of $ 20, 10 and 5 which will be exchangeable upon demand against coins. The new bill is known as the Demand Note.
The government is cautious : this Demand Note is the first federal bill that does not bear an interest. As such, it is the first modern note of the United States.
The note must be signed by two officials. The huge amount of small bills requires to entrust this work to employees who do not sign in their name but by procuration, respectively 'for the' Register of the Treasury and 'for the' Treasurer of the United States.
Employees are hand writing 'for the' after their own signature. This process doubles the time spent on each piece and is not tolerable. It has been told (but it is not proven) that they then contemplated to imitate the signature of the officials to remove 'for the'. It was easier to print 'for the' and this solution was put in place less than a month after the start of the operation.
The Demand notes with the handwritten 'for the' are thus the very first modern federal notes of the United States, and they are rare in all denominations. For the highest value, $ 20, the note coming for sale is the only one known with the handwritten 'for the'.
War is expensive. The government soon had to suspend the redeeming of coin on demand and stopped issuing Demand notes in April 1862. The Legal tender notes that succeeded them maintained the new tradition of a green back.
SOLD for $ 336K including premium