This subseries contains letters written to, by, and about Francis L. Lee, including correspondence related to his role as the colonel of the 44th Regiment of the Massachusetts Volunteer Infantry during the Civil War. It also includes several letters written to his son Francis W. Lee, as well as a small assortment of personal documents.

Correspondence from 1838-1840 relates primarily to Lee's studies, including letters to his father Henry Lee and mother Mary Jackson Lee, from Samuel A. Ripley and from Josiah Quincy concerning Francis L. Lee's studies and difficulties at Harvard. In 1844, Lee wrote a letter to his friend Thomas B. Hall describing his travels in Rio de Janeiro as a supercargo for the family trading business. An 1845 account book and letterbook document Lee's family business dealings in India, including the purchase of silks, linseed, and general merchandise.

Correspondence from 1847-1859 deals primarily with personal and family matters. His primary correspondents include Mary Jackson Lee, Henry Lee, brother Henry Lee (1817-1898), sister-in-law Lizzie Cabot Lee, and friend Thomas B. Hall. One major subject is the building, outfitting, and remodeling of his country home, "Stoney Sides," located near Lake Champlain. Other subjects include family news, such as his marriage to Sarah Wilson Lee, visits to friends, the birth of his daughter Mary Lee (later Hale) in 1849, the birth of his son Francis W. Lee in 1852, and the birth of his daughter Alice Lee in 1854. Additional topics include farm life and agriculture, Lee's finances, the economic effects of the railroads, and Lee's 1853 trip through Philadelphia, Washington, D.C., Virginia, Kentucky, and Cincinnati, in which he discusses slavery and his impressions of the South.

After 1860, Francis L. Lee's correspondents are more varied. Throughout the Civil War, Lee received letters from his wife Sarah Wilson Lee concerning the war's progress and family life at home. Lee's children Francis W. Lee, Mary Lee, and Alice Lee wrote about their daily activities and the war. Throughout the war, other officers wrote Lee letters concerning personnel, and several of the men that served under him requested letters of recommendation. Another frequent correspondent was E. J. Hunter, who was responsible for Lee's business matters at home. Several correspondents, including Charles Russell Lowell, wrote to Lee about the formation of African American regiments, and a series of 1864 letters discuss an expedition to collect specimens in Bermuda undertaken by Albert S. Bickmore for Louis Agassiz. Other letters relate to Francis L. Lee's role as a military advisor at the Massachusetts State House in 1865.

Several legal documents, including mortgages, quit-claim deeds, and discharges of mortgages, are located in this subseries. A folder of papers related to Francis W. Lee includes a quit-claim deed and a letter electing him treasurer of the Trustees of Phillips Exeter Academy.

This subseries contains handwritten scenes from various plays in which Francis L. Lee performed, including The Waterman, Perfection, The Rivals, The German, Good Night's Rest, Turn Out, Damon Pythias, and Who's the Dupe.

This subseries includes drawings sent to Lee by his children during the Civil War, as well as house plans drawn by Lee.