This collection was accessioned with the John S. Hill Family Papers in 1987. The donor is unknown. The collection was made a separate collection in 2019.
Seven of the letters were transcribed for the article "Some Letters of William Dunlap Simpson 1860-1863" by Willard E. Wight. The South Carolina Historical Magazine, Vol. 57, no. 4 (1956): 204-22. http://www.jstor.org/stable/27566082. These letters are indicated here with an asterisk*.