This collection consists of one diary from 1865 written by Walster and transcribed true to text, meaning all grammatical errors and misspellings replicate Walster’s original writing. The diary has been digitized and is accessible from the New York Heritage Digital Collections.

The diary begins with Walster rejoining his regiment in the Shenandoah Valley after returning from a furlough. Subsequent entries include information such as, weather conditions, rations, attending church meetings offered by the Christian Commission, letters sent or received, occasional poems and serving on picket duty while encamped. In April, Walster was hospitalized at Jarvis Hospital in Baltimore, Maryland and diary entries over the next three months record his recuperation, various medications given him, and helping other patients in the hospital. His most notable entries written during this time are about the assassination of President Abraham Lincoln, and Walster’s reaction to that event and those involved with the assassination. After his discharge in June, the diary continues with his civilian life, and includes entries about the weather conditions, visiting friends and family, attending church and other social activities, and working as a clerk. The last entry was written on December 31, 1865.

The back of the diary contains financial accounts indicating his spending pattern, and a summary of his military service from his enlistment in 1862 through his discharge in 1865, which includes a furlough home in June 1864 due to sickness and remaining there through the end of the year. He also identifies locations where his regiment was stationed at, such as Alexandria, Virginia, Washington, D.C., and New Orleans, Louisiana. The flyleaf and endpaper contain names, addresses, calculations, and an upside-down American flag.