The collection contains eight original diaries, as well as transcripts and additional biographical information. Harville's diaries chronicle his experiences with the 7th Wisconsin Regiment during 1861 and 1862. He spent much of 1863 and 1864 in Newton University Hospital, and later Jarvis Hospital, in Baltimore, Maryland, facing chronic illness.

Clearly intended for an audience, the diaries contain short addresses to the "Reader" at the beginning and end, often including an apology for his poor grammar and spelling. Largely self-educated, Harville's diaries are surprisingly legible and his phonetic spellings are easy to decipher. Most of the diaries also include a list of letters received and written, as well as Harville's cash and barter accounts with friends. Several diaries are indexed and/or paginated.

Harville's early entries detail the formation of Company F in Lancaster, Wisconsin, travel to Washington, DC, and life in camp outside Alexandria, Virginia. Like many farmers in the war, he keeps consistent notes on the weather. He recounts stories of his own adventures which more than once landed him in trouble, as well as the exploits of others. He also writes of picket and guard house duty, the occasional scouting mission, frequent drills and dress parades, and war news. He remains relatively well-informed about the war, at least in as much as it related to his experiences and his regiment.

While spending time in Jarvis and Newton University Hospitals, the content of his entries begins to change some. He continues to records war news of note during this period, but the emphasis is on the work he does and the social life he develops. His illness is intermittent and so he also does chores around the hospital, including cleaning inside and outside the buildings, cooking and serving, and running errands. Harville spends a good deal of time helping the local women who volunteer at the hospitals, too, which he appears to thoroughly enjoy. At least two diaries contain a list of women and young ladies with whom he is acquainted.