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.