Correspondence, mainly addressed to Francema Mason, including letters from Otis Mason during his Civil War service with the 129th Illinois Infantry in the South.

Otis Mason's Civil War letters indicate that he marched to Bowling Green, Kentucky in November, 1862. The 129th Regiment reached Mitchellville, Tennessee as a garrison unit in December, 1862, and they reached Nashville, Tennessee by October, 1863. Otis Mason marched across Georgia in 1864 to join the army under the command of General Sherman. The letters largely consist of his concerns for his wife's well-being and details of his daily routine. Otis Mason also discusses the regiment's movements and comments on Union generals such as Sherman and Rosecrans. Many of the letters are cross-written.

Unless otherwise specified, all other letters from friends and family are addressed to Francema Mason. A friend originally from Fairbury, Illinois and who had moved to Topeka, Kansas writes of the women's suffrage movement in Kansas in 1876. A relative writes about Native Americans and the gold rush from Deadwood, South Dakota in July, 1876. A wedding invitation for the 1873 wedding of Daniel Crompsey and Nora Caldwell is also included.