Central to this collection of family letters are personal letters written by Marcellus Ovando Messer during his Civil War era military service in Company C, 19th Ohio Infantry (1861-1865). These letters date from 11 January 1862 to 23 October 1865. Stamped, postmarked envelopes are present for most. Messer writes to his parents Loren S. Messer and Chestina W. Cook Messer and younger brother, Charles Messer, at home in Warren, Ohio, and to his brother George W. Messer (who by 1863 was himself serving in the army). Each letter describes events which have transpired since the preceding letter, and share Messer’s observations and reflections on army life and the war. Topics of discussion include troop movements, battles fought, camp conditions and rumors, Messer's health and diet, and descriptions of towns and terrain. Messer also writes of his support for the Union cause, and his reports home remain unflaggingly positive throughout his enlistment. He also discusses his consistent avoidance of the "vices" he observes in camp. Messer frequently relays news of the “Warren boys,” soldiers from his hometown serving in his and other companies. One Civil War era letter from a cousin "Myron" to George W. Messer is filed with Marcellus Ovando Messer’s letters.

The collection also includes correspondence sent and received by Messer relatives with the surnames Dickey, Humphrey, and Sleeper between 1853 and 1924. These include condolences received by Fannie Messer following the death of her father, Samuel Fisher Dickey, in 1900 and 5 letters from Sara Humphrey, a teacher at Tougaloo University, to Fannie Messer's aunt, Hannah Jane Sleeper, during Reconstruction.