The Otis family papers consist of 39 letters written home by several Civil War soldiers between November 30, 1861, and December 2, 1862. Louisa Otis and her parents are the most frequent recipients. Louisa's brothers, Ferdinand and Israel, wrote the majority of letters in the collection; her cousins, Dudley Otis and Mortimer S. Roberts, also contributed several letters each. The brothers sometimes collaborated in their letters, each writing a portion, thereby giving two perspectives on events.
Early letters repeatedly reference pay, health, and camp life. On January 3, 1862, Ferdinand wrote to his parents concerning the rapid spread of mumps through the camp and reported that he had been vaccinated, likely against smallpox, and was very sore. Both brothers frequently anticipated upcoming paydays and how much they would send home, and requested items such as mittens. On February 2, 1862, Ferdinand provided a detailed description of how soldiers laundered their clothes.
By mid-1862, the correspondence had become more focused on battles, injured and dead comrades, and the hardships of war. A letter from Israel, Ferdinand, and Otis gives a description of the Battle of Williamsburg, which Israel called a "long and bloody struggle," which lasted into the evening. He also recalled the Union band's performance of "Dixie," and the cheers of the soldiers, which "must have sounded anything but pleasant" to the Confederates (May 12, 1862). Another letter, dated June 7, 1862, references the Battle of Fair Oaks, in which the 57th Pennsylvania Infantry lost several officers, including Major Jeremiah Culp. Ferdinand described the morale of the soldiers, noted "we have got only our field officer left," and gave an account of the stench of rotting corpses in the woods. Israel noted that a bullet went through Ferdinand's coat and that his haversack was shot open, scattering his belongings. Other correspondence documents receiving family photographs (August 30, 1862), finding Southern cows to milk (November 28, 1862), and desiring more letters from home.