This series consists of correspondence between members of the Slade, Rogers, and related families. Correspondents include Benjamin Slade (d. 1813), his second wife Susanna Tilton Slade (1741-1808); and their children William, Samuel, John, Susanna, Mary, and Jacob Tilton. Of particular interest is correspondence between Benjamin Slade and his son William in Tobago from 1788 to 1789, including letters discussing the ratification of the U.S. Constitution and the emerging American system of government. Other subjects include the day-to-day life of the family, religion, travel, and death.

Correspondents among the Rogers family include Daniel Denison Rogers (1751-1825); his wife Elizabeth Bromfield Rogers (1763-1833); his wife's father Henry Bromfield (1727-1820) and brother Henry Bromfield (1751-1837); and Daniel's sister Martha Rogers (d. 1840). Also included are Daniel's children and their spouses: Elizabeth Rogers Slade (1798-1826) and her husband Jacob Tilton Slade (1778-1854); Henry Bromfield Rogers (1802-1887?) and his wife Ann Perkins Rogers (1805-1880); and Hannah Rogers Mason (1806-1872). Many letters dating from the 1830s are written between the children of Jacob Tilton Slade and Elizabeth Rogers Slade: Daniel Denison Slade (1823-1896), Elizabeth Bromfield Slade Schmidt (1821-1880), and Mary Ellen Slade (1823-1845). This correspondence provides insight into educational practices during the time, as well as the children's relationships with their aunts, uncles, and cousins. The letters also discuss Daniel Denison Slade's education at Harvard and travels abroad.

A large portion of the family correspondence dates from 1860-1870 and consists of letters from Daniel Denison Slade to his wife Mina Louise Hensler. Subjects include daily activities, travel throughout Europe and the United States, relations with various family members, and the health and hobbies of their twelve children. Correspondence to and from their children, Denison Rogers Slade (1857-1914), Ellen Louise Slade (b. 1860), and Margaret Bromfield Slade (b. 1862), can also be found here, as well as letters by Margaret Bromfield Pearson Blanchard (1787-1876).

Letters to Mina Hensler Slade from her sister Elise Hensler, the Countess d'Edla (1836-1929), begin around 1860 and continue through 1918. This substantive portion of the collection details Elise's marriage to Ferdinand II, former king of Portugal; her financial troubles with the royal family after his death; the revolution in Portugal; the exile of the royal family in the early 1900s; and the raid of her home during World War I. Her wax seal, containing her coat of arms, can be found in good condition on a letter dated 27 October 1872. Also included are single letters from Dom Pedro II of Brazil in 1876 and Ferdinand II of Portugal in 1879.

Also found in this series are resolutions, prayers, and remembrances.

This series contains the personal, non-family correspondence of Jacob Tilton Slade, Daniel Denison Slade, Henry Bromfield Rogers, and others. It includes an 1827 letter to Jacob Tilton Slade from William Ellery Channing, as well as papers related to the education of Daniel Denison Slade and Elizabeth Slade Schmidt (1835-1837), including letters of Joseph and Lucy Clark (Ware) Allen, report cards for the children, and undated letters from Dorothea Dix. The series also contains letters from Sophia Willard (Dana) Ripley and an unidentified girl at Brook Farm to Mary Ellen Slade (ca. 1840); letters from Daniel D. Slade to Ariana Walker (1846-1847) and Francis Parkman (1888-1890); an 1859 letter from Samuel Abbott Green to Daniel D. Slade; an 1872 letter from Eliza Susan Quincy; and undated letters from Ezra Stiles Gannett. Several letters, primarily letters from William Harrison to Henry B. Rogers beginning in 1837, discuss the death and property of Henry Bromfield. There is also some correspondence with Thomas Dwight in Paris regarding the funeral arrangements and tomb of Jacob Tilton Slade in 1854. Denison Rogers Slade is responsible for much of the correspondence after 1897, which is primarily concerned with tracking the ancestry and effects of the Slade-Rogers family and includes correspondence with Edward Wheelwright.

This series consists of manuscript writings of Daniel Denison Slade and his sister Mary Ellen Slade. Writings of Mary Ellen Slade include stories and essays about country life, the natural world, New England, history, and other subjects, probably written for school, ca. 1840. Writings of Daniel D. Slade include an 1869 article about Class Day at Harvard and undated histories and descriptions of Northborough, Princeton, and Harvard, Mass.

This series consists of papers related to the patent held by Jacob Tilton Slade for a mining elevator he invented in 1832. It includes letters, a diagram, and a volume containing a narrative description about the invention of the machine in 1832. Slade's "Memoir of the Invention of a Machine" describes the creation of an elevator designed for the safe transportation of men and materials up and down mine shafts and the process of obtaining a patent, and contains copies of correspondence with those people instrumental in the machine's development.

This series contains legal and financial documents, including early deeds for land in Portsmouth, N.H.; receipts from land purchases and transactions of Benjamin Slade; a small account book of stock broker Edward A. Pearson (1828-1830); receipts related to the guardianship of Daniel Denison Slade (1835-1836); estate documents and the will of Henry Bromfield (d. 1837); and a record of a donation of volumes to Harvard University by Daniel Denison Slade (1844).

This series contains genealogical research notes and other papers regarding the Rogers, Slade, and related families. Notes were compiled by Daniel Denison Slade and continued by his son Denison Rogers Slade. Also included in this series is a manuscript autobiography of Major Daniel Denison written in 1672, a handwritten index of biographical sketches, a photocopy of a typescript memoir of Elizabeth Rogers Slade by Henry Bromfield Rogers, an "account of old Portsmouth people" by Mrs. Ichabod Goodwin, biographies of Daniel Denison Slade, family trees, and notes about family heirlooms and portraits.

This series contains cutslip autographs, autograph letters, and an autograph book. Included are autographs of Slade-Rogers relatives, as well as Oliver Wendell Holmes, Henry Wadsworth Longfellow, Louis Agassiz, Francis Parkman, and others. The autograph book was signed by Fernando II of Portugal, members of his family, and other European royals and nobles in 1875-1880.

Printed material includes biographical sketches of Daniel Denison Slade and others; Captain John Bonner's 1722 map of Boston; an 1828 list of members of the First Church of Christ in Portsmouth, N.H.; an 1832 pamphlet by I. H. F. Blanchard entitled The Christian Doctrine of Regeneration; the Dec. 1873 edition of the newspaper The Tea Cup commemorating the 100th anniversary of the Boston Tea Party; an 1878 list of steamship passengers; Harvard appointments to Daniel D. Slade; reviews of his "The Evolution of Horticulture in New England"; directions on the preservation of teeth; and newspaper clippings. The series also contains an undated printed transcript of the 1672 autobiography of Major Daniel Denison located in Series VI.