The majority of the collection is the correspondence series. The letters of Thomas Barclay (1753-1830) concern politics, legal matters, family news, business and financial matters, observations on life in America and its citizens after Barclay relocated there from Canada, the escheating of his lands in Nova Scotia after his removal to New York City, and his service as a commissioner appointed to settle the disputed boundary between the United States and Canada. There is also a substantial amount of correspondence concerning the receipt of his pension from the British government. The letters of his son George Barclay (1790- 1869) concern family news and health, financial matters, the estate of his mother-in-law Matilda Lockhart Aufrere (1774-1850), and the sale of family lands in Nova Scotia. There is also correspondence of his brother Henry Barclay (1778-1851) containing family news and information on financial matters. Also included in this series is correspondence of William Cabell Rives (1793-1868) while he was serving as United States Senator from Virginia. The letters are written to his wife Judith Page Walker Rives (1802-1882) and his son Francis Robert Rives (1822-1891). Topics covered include the tariff, appropriations, the Webster Treaty, the presidential election of 1842, Virginia politics, Edward Everett's political career, his own speeches in the Senate, the resignation of Daniel Webster as Secretary of State, reorganization of President Tyler's cabinet, Democratic Party politics, his son's future plans, the annexation of Texas, his opinion of James K. Polk, the appointment of James Buchanan as Secretary of State, and the death of his father Robert Rives (1764-1845).

The bulk of this series, however, is the correspondence between Francis R. Rives and his wife Matilda Antonia Barclay Rives (1824-1888) and their son George Lockhart Rives (1849-1917) while the latter was a student at Trinity College in Cambridge, England between the years 1868 and 1871. Included are descriptions of his school, his classmates, and the city of London, his social and recreational activities, most notably sailing, his trips to the Continent, his finances and school expenses, the weather, family news, and his parents' trips to Europe. There are also letters written to him by Hamilton Fish (1849-1936) while the latter was serving as private secretary to his father who was United States Secretary of State.

The subject files contain a variety of material on the Aufrere, Barclay, DeLancey, Lockhart, and Rives families. Included are calling cards and invitations, information on the dower claim of Margaret DeLancey who was the widow of James DeLancey, estate papers, genealogical notes, military service records, the pension claim of Susan Barclay who was the widow of Thomas Barclay, speeches, and the wills of Matilda Lockhart Aufrere and Thomas Barclay.

Most of these items relate to the work of George L. Rives. Included is the manuscript copy of his valedictory address at Columbia College (1869), articles on the United States and Mexico relations, which he wrote a book on, essays he wrote while at Cambridge, and various pamphlets containing speeches by members of the U.S. House of Representative and Senate, including his grandfather, William Cabell Rives. Many of these concern the annexation of Texas.

The ledgers and letterbooks were kept by Anthony and Matilda Aufrere, Thomas Barclay, George Barclay, and George L. Rives. Those belonging to Anthony and Matilda Aufrere contain various pieces of verse and prose. The letterbooks of Thomas Barclay contain his official correspondence while he was stationed in New York serving as British Consul-General for the Eastern States off America. There are 13 volumes. The last volume also contains letters written while he was serving as a commissioner under the fourth and fifth articles of the Treaty of Ghent to settle the ongoing dispute over the Canadian-U.S. boundary. Portions of these letterbooks were published in Selections from the Correspondence of Thomas Barclay - Formerly British Consul-General at New York by George Lockhart Rives (New York: Harper & Bros., 1894). Also included in this series are three letterbooks of George Barclay covering the years 1850-1856 and 1861-1868 while he was a merchant in New York. There is also a ledger of George L. Rives containing official correspondence, proceedings, and regulations while he was serving as Assistant Secretary of State for Latin American Affairs from 1887 to 1889.

The prints contained in the collection deal with the Mexican War. There are also family photographs and photographs taken on a trip to Mexico, as well as a family photgraph album, and a photograph album of various New York officials, circa 1904.

The oversize items include deeds, estate papers, newspapers, passports of George L. Rives, promissory notes, a family register of the Whiting family, the wills of George Anthony Aufrere, Susan Barclay, Oliver DeLancey, Mary Huguetan de Gastine, and John Norris, and miscellaneous items.