The 23rd Regiment Massachusetts Volunteer Infantry Association records include meeting minutes, correspondence, reunion programs and invitations, scrapbooks, photographs, and newspaper clippings created and collected by elected officers and members of the 23rd Regiment Association. The collection has been arranged into three series.

The Herbert E. Valentine Papers includes scrapbooks, diaries, correspondence, sketches, photographs, printer's blocks, newspaper clippings, and books created by Valentine both during and after the Civil War.

The Massachusetts Volunteer Militia Records includes orderly books, rosters and enlistment records, quartermaster accounts, guard report books, general orders and brigade orders, muster rolls, company descriptive books, and correspondence. This collection has been arranged into twenty-two series based on regimental distinctions.

The Union Drill Club of Salem Records include constitutional documents, members lists and rosters, records, and account books. This collection has been arranged into one series.