This series contains nine volumes of Richard Frothingham’s journals. They contain discussions on local and national politics including the National Bank Crisis, the Tyler Presidency, the Democratic Party, and the Whig party; social issues including capital punishment and slavery; and personal subjects such as philosophy, current readings, and daily activities. Frothingham's diary kept, Dec. 28, 1839-Jan. 29, 1840 contains newspaper clippings pertaining to the Massachusetts State Legislature and records issues pertinent the legislative session for that year.

This series contains documents relating to early colonial history, including marriage contracts and muster and payroll for the Continental Army, indenture contracts, and his grandfather Richard Frothingham’s correspondence regarding pension for service during the Revolution. Other items include a draft of an article "Discovery of America by the Northmen", and an official appointment as Inspector of State Prisons. Correspondence includes first hand accounts of the Battle of Bunker Hill, Frothingham's tenure as mayor of Charlestown, possible nominees in the 1852 presidential election, and Frothingham's unsuccessful run for U.S. Congress. Also includes documents relating to his election as delegate to Democratic National Convention, a letter supporting the Irish Nationalists, a letter of condolences to Mrs. Frothingham over the death of Richard Frothingham, a scrapbook of newspaper clippings relating to his published works and his newspaper articles, and a volume commemorating Major William F. Clark of the 30th Mass. Infantry.

This series contained annotated published works by Richard Frothingham interleaved with notes, manuscript corrections, and illustrations.

This series contains documents relating to Richard Frothingham's research for his publication, History of Charlestown. These documents are loosely arranged chronologically under the topical headings used by Richard Frothingham to organize his notes.