James Oliver Longstreet's personal diary from the year 1856 covers the second semester of his junior year at Wesleyan, as well as the first semester of his senior year. Many events are recorded in the diary, including the 1856 presidential election and the founding of the Middletown chapter of the Alpha Delta Phi fraternity. Longstreet also discusses his work as a teacher in North Guilford, Connecticut and North Branford, Connecticut.

The single volume of the Young Men's Republican Club of Wesleyan University records consists of an account of the activities of the club in the first year of its existence, 1856. It includes the group's constitution and minutes of meetings.