In December 1864, a black soldier named Morgan W Carter wrote a long, affecting letter to a friend, detailing his thoughts concerning the key issues of the day - the American civil war and racial equality.
Referring to Abraham Lincoln as "uncle Abe", Carter explores ideas of duty and equal opportunity throughout the missive, casting light on what it would have been like to live as a soldier during politically turbulent times.
The letter, which carries a $6,000-8,000 estimate, is to auction in New York on March 21.
After "being trampled under the white man's heal for years," writes Carter, "now we have a choice to elevate our selfs and our race and what little I can toward it I will do so most willingly.
"If I should die before I receive the benefit of it I will have the consolation of nowing that the generations to come will receive the blessings of it. And I think it the duty of all men of our race to do what they can."
Earlier this month British actor Daniel Day-Lewis was awarded his third Oscar for Best Actor for his performance as Abraham Lincoln in Steven Spielberg's latest historical blockbuster, Lincoln, propelling the American civil war back into the spotlight.
Artefacts and documents relating to the civil war have been considered hot property among collectors for many years. A collection of letters once belonging to combatant Isaac Plumb - who did not survive the war - sold for $46,000 in October 2012.
Personal letters tell us a great deal about the periods in which they were written, as well as the people who wrote them. Our sister company, PFC Auctions, is currently offering four groundbreaking letters authored by Nobel Prize winning physicist Albert Einstein during the cold war. As bidding ends this evening, we advise interested parties to act fast.
Sign up for our free weekly newsletter.