Unpublished letter by Abraham Lincoln discovered in Pennsylvania

Short, handwritten note was for Charles Ellet Jr, who had written to the president for a civil engineer corps during the civil war

A previously unpublished letter written by Abraham Lincoln during the civil war has been discovered and put up for sale in Pennsylvania, offering rare insight into the US president's strategic thinking in the first year of the conflict.

The recipient of the short, handwritten note was Charles Ellet Jr, later a colonel in the Union army who wrote to Lincoln seeking the formation of a well funded civil engineer corps to help fortify Washington DC against the Confederate threat.