The papers of Thomas D. Kimball span the period 1851 to 1867 with the majority of the papers dating from 1862 to 1865. They consist primarily of official communications and documents relating to Company A, 2d Massachusetts Heavy Artillery and Company G., 51st Massachusetts Volunteer Militia Infantry, during the period they were occupying New Bern, N.C., after its capture by Union troops. Kimball was Captain first in the 51st Regiment and later in the 2nd Massachusetts Heavy Artillery Regiment. The collection is divided into five series: correspondence; financial papers; orders; regimental reports; and miscellany.

Regimental reports comprise the bulk of the collection and are divided into two subseries, personnel and other monthly and quarterly reports, concerning the companies' supplies. Personnel records include returns (reports indicating changes in company personnel), records of target practice, volunteer enlistment papers, descriptive lists, and discharge papers.