The bulk of Hannah's family correspondence is with her sons, William Powell Mason (1850-1870) and Edward Bromfield Mason (1857-1863). Letters from William (known as "Powell") describe his first year at Harvard University in 1852 and his 1856-1859 trip to Europe, including Vienna and Paris. Beginning in 1861 Powell's letters primarily describe social activities in Washington, D.C., and after October, his actions at the headquarters of the Army of the Potomac, including news of the war, camp life, and social activities. They contain detailed descriptions of Union troop activity and military strategy in Washington, Alexandria, the Fairfax Court House, and Camp Winfield Scott in Virginia. Powell describes his interactions with Gen. George B. McClellan and his esteem for him, frequently mentioning Boston soldiers that his mother knows. He also mentions President Lincoln's visit on 9 July 1862 to the headquarters' camp on the James River.

Hannah's war correspondence with her son Edward ("Ned"), an assistant surgeon in the 14th Regiment of Mass. Volunteers, is not as detailed. Of note are a December 1862 letter discussing Washington social life and a 27 March 1862 letter describing the Union base camp under Gen. McClellan at the Alexandria Seminary. After transferring to a cavalry unit, Ned was killed in a riding accident in 1863.

For additional Civil War correspondence among William P. Mason Jr., Edward B. Mason, and William P. Mason, Sr. see Series III, Mason family papers.

Also in this series is Hannah's correspondence with her brothers Henry Bromfield Rogers and John Rogers, niece Mary Ellen Slade, nephew Daniel Slade and his wife Louise Hensler Slade, sister-in-law Mary B. Parkman, brother-in-law Jonathan Mason, daughter-in-law Fanny Mason, and cousins Elizabeth and Charlotte Grant.

For correspondence between Hannah Rogers Mason and her daughter Elizabeth (Lillie) Rogers Mason Cabot, see Series IV. A., Elizabeth Rogers Mason Cabot papers - Correspondence.

Hannah Rogers Mason's personal papers include correspondence with friends Anna C. Webber, Mary C. Steele, M. B. Blanchard, and Annie Hinkley. Also in this series are an 1833 account of the final illness and death of her mother, Elizabeth Bromfield Rogers, financial accounts, personal correspondence regarding financial and household matters, and several letters from Rev. Ezra Stiles Gannett of Federal Street Church regarding her charitable contributions.

Volumes include Hannah Mason's book of essays composed at the Boston Lyceum for the Education of Young Ladies. It includes topical essays with comments by her teacher, as well as a list of medals she received. A small commonplace book holds copies of literary quotations.

Hannah's diaries consist of nine volumes dating from 1853 to 1871. Entries describe her son Edward's fatal accident in Sep. 1863 and the death of her husband William in Dec. 1867. Two 1853 volumes contain an account of Hannah's trip with her husband and daughter to Naples, Rome, Florence, Vienna, Germany, Flanders, and London. Volumes dated from 1863 to 1868 are pocket diaries containing brief accounts of her daily routine.

Hannah's journal “Notes on my visit to Europe in 1868” records her trip to England, Belgium, Germany, and France with her daughter and son-in-law, Elizabeth and Walter Cabot. Beginning on 30 May 1871, entries were written by Elizabeth Cabot as a record of her mother's declining health and her death on 19 June 1871.

The bulk of Elizabeth's correspondence consists of that with her mother Hannah Rogers Mason; her sister-in-law Elizabeth "Lizzie" Dwight Cabot, the wife of J. Elliot Cabot; her brother William Powell Mason; and her friend Marian Hovey. Smaller but significant amounts of correspondence include that with her mother-in-law Eliza Perkins Cabot and her brother Edward "Ned" Bromfield Mason. Additional family correspondents are her brother-in-law Samuel Cabot, her aunt Mary B. Parkman, her uncle Henry Bromfield Rogers, her sister-in-law Eliza “Bessie” Perkins Cabot Lee, cousins Daniel Denison Slade and Louise Slade, and her niece Fanny Mason. Personal correspondence includes that with friends Fanny Cary, Anna Webber, Loulie Gardiner, Mary Apthorp Quincy (daughter of Boston mayor Josiah Quincy), Jennie Revere (Reynolds), Susie Welles (Sturgis), Nathalie E. Baylies, and Grace Heath. With the exception of correspondence from March 1873 when Walter C. Cabot traveled to the southern United States, including Charleston, Savannah, and St. Augustine, only a small amount of correspondence exists between Elizabeth and her husband since the two were seldom apart.

Subjects primarily consist of news of family and friends, social activities, and descriptions of travel. Large amounts of correspondence surround Elizabeth's trip to Europe from 1852 to 1854, her Jan. 1857 trip to Washington, D.C., her engagement to Walter Cabot in Dec. 1859, their subsequent marriage in June 1860, her travels in Europe from 1867 to 1870, the illness and death of Elizabeth's father in Dec. 1867, her daughter Mabel's surgery in London in April 1881, and Elizabeth's trip to Europe from 1885 to 1886.

A small amount of correspondence has been transcribed, most likely by Elizabeth's daughter Ruth Cabot Paine. These transcriptions are filed with the original correspondence. Several transcriptions do not correspond to originals in the collection; the location of the original letters is unknown.

This subseries consists of thirty-five diaries of Elizabeth Rogers Mason Cabot, kept from 1844 to 1896. Her most extensive entries date from about 1845 until her marriage in 1860. Entries describe her winter activities in Boston and later Brookline, Mass. and her summers in Newport, R.I., Walpole, N.H., the White Mountains, Manchester, Mass., and coastal Maine. She also discusses her education, courtship, church attendance, engagement to Walter Cabot, household management issues, child rearing, family news and health, weather, social engagements, thoughts on the education of women, anxiety over life and marriage, and religious thought.

Descriptions of her extensive travels include her 16-month European trip with her parents in 1852 and 1853 through England, Scotland, the Netherlands, Switzerland, Italy, France, Austria, and Germany, include great detail about the cultural institutions they visited and a description of parades for Louis Napoleon. Elizabeth also describes her trip to Washington, D.C. in 1857, her travels in Europe from Dec. 1867 to June 1870, and again from 1885 to 1886. The diaries also contain a detailed description of her daughter Mabel's diagnosis and surgery for an ovarian tumor in London in 1881.

Some of the diaries have been transcribed, most likely by Elizabeth's daughter Ruth Cabot Paine. These transcriptions are foldered with the original diaries. Several transcriptions do not correspond to originals in the collection; the location of the original diaries is unknown. Excerpts from Elizabeth's diaries have also been published in P. A. M. Taylor's More than Common Powers of Perception: The Diary of Elizabeth Rogers Mason Cabot (Boston, 1991.)

Included is Walter C. Cabot's correspondence with his mother Eliza Perkins Cabot and father Samuel Cabot, as well as correspondence with his sister Sadie Cabot Wheelwright, brother J. Elliot Cabot, sister Elizabeth Perkins Lee, and brother-in-law Henry Lee. Correspondence largely dates from the 1850's with subjects including Walter's engineering education, his efforts to find accommodations in Paris, news of family activities, and concerns for Walter's health. Additional correspondence includes that with his mother during his trip to Europe from 1867 to 1868.

Personal papers include financial accounts and personal correspondence, including that with Mary and John Gardiner, William Nye Davis, Augustus Lowell, and E.L. Baylies. An 1851 letter from Thomas Jefferson Coolidge describes the Boston social scene. Letters dated from 1859 to 1860 congratulate him on his engagement and wedding.

For Walter Cabot's correspondence with the Mason family, including William P. Mason, Hannah Rogers Mason, and their sons, William Powell Mason and Edward B. Mason, see Series III, Mason family papers.

Samuel Cabot (1784-1863) was the father of Walter C. Cabot and the husband of Eliza Perkins Cabot. His 1851-1852 diary contains a brief narrative and expense accounts for his travels to England, France, and Italy and his return voyage to America.

This subseries includes the correspondence of Walter Cabot's mother, Eliza Perkins Cabot, with her sister Mary Perkins Cary and niece M. E. Walker; letters to Walter's brother, Louis Cabot, from his wife Amy; copies of letters from Walter's brother, J. Elliot Cabot, to his son and daughter-in-law, and letters to Walter's sister, Elizabeth Perkins Cabot Lee, from her daughter.