The Correspondence series consists of 167 personal and business letters of Elijah Boardman and his family. Many of the letters are copies sent to Eli Baldwin, who managed Boardman's property in Ohio. Oliver Wolcott, from the Connecticut Council Chamber, sent multiple letters (1818, 1820) informing Boardman of his elections to state office. The collection also contains letters between friends and family members, including a number of items between Elijah and his son William, who was studying at Harvard College in Massachusetts, and letters to and from William's brother George and his mother Mary ("Mama"). In addition to the Boardman material is a small set of fifteen 20th century letters pertaining to Walter G. Drogue, comprising.
The Documents series contains 10 items, mostly inventories of Boardman's estate and property, along with his last will and testament.
The Business and Financial Papers series of 163 items consists of promissory notes, tuition receipts from Harvard and Yale, correspondence on orders and shipments from Villee and Burrail, and miscellaneous receipts and financial accounts.
The Miscellaneous: Political and Other series holds 30 items, both related to Boardman's public work as well as some truly miscellaneous items, such as a poem titled Oh Unfortunate, and a printed list of prices for produce in New York. Two items of note are a booklet with a list of names of "Freemen Republicans" and "Freemen Federal," and Boardman's Political Notebook from 1803.
The Drafts, Research, and Notes and series contains an undated manuscript draft of Walter Gerald Drogue biography of Elijah Boardman and the the materials he used to write the history. This series is comprised of 1,848 dated and undated items such as letters from libraries and special collections detailing their related holdings, and note cards with citations from primary and secondary sources.
The Books series contains two volumes: William Boardman's "Commonplace Book," which mentions topics such as philosophy, astronomy, and poetry; and the published Memoir of the Life and Character of Mrs. Mary Anna Boardman, with a Historical Account of Her Forefathers, and Biographical and Genealogical Notices of Many of Her Kindred and Relatives, by John Frederick Schroeder, published in New Haven, in 1849.