This collection is composed of records which relate to Southborough’s militia, and document the town's role in military conflicts from the Revolutionary War forward.

There is considerable documentation relating to the Revolutionary War, including enlistment records and payment stubs for local men who served in the continental army. The town’s records relating to the Civil War are even more expansive and provide extraordinarily thorough accounts of local soldiers and their service. A total of 219 men from Southborough enlisted in the war, which was 33 more than needed to fill the local quota called for by President Lincoln. The records include lists of volunteers, regiment rolls, certificates of mustering officers, lists of recruits who had been accepted by the examining surgeon, physical descriptions of soldiers, their birthdates, names and contact information for their nearest relatives, biographical sketches and service descriptions of local men who served in the war, and the names of persons who donated money to support the town’s military fund.

These military records are complemented by annual militia lists which span from 1827-1933. The lists provide the names of persons enrolled in the town militia, and of those who were liable to be enrolled. Some lists include ages, occupations, and other remarks in addition to names.