The author of this letter in the Resources section, Elizabeth Blair Lee (left, 1818-1906) was the daughter of Francis Preston Blair, middle sister of Montgomery and Frank Blair, and wife of Union naval officer Samuel Phillips (Phil) Lee (right, 1812-1897). These portraits were done by noted artist Thomas Sully.
Elizabeth wrote to her husband nearly every day while he was away on duty. Phil would rise to the temporary rank of rear-admiral during the war, and attain that level permanently again after the war.
Elizabeth and Phil lend their name to the combined Blair-Lee house across the street from the White House - it currently houses visiting heads of state. The left half of the house was first a wedding gift from Blair Sr. to his daughter and son-in-law. I wrote a little bit about the Blairs and the house here and here.
You can read a more detailed biography of Elizabeth here.