The Riley family papers (2,902 items) document the personal and business activities of Ashbel Wells Riley and his son George Stillson Riley of Rochester, New York. The papers concern family relationships and society in western New York, as well as the Riley's participation in the temperance movement, and George Riley's involvement in the Grand Council of the Iroquois.
The Personal Correspondence series (356 items) consists primarily of letters to Ashbel W. and George S. Riley, from friends and family members. Included are several letters from Charlotte to her husband Ashbell, when he was traveling in Europe in the 1840s; letters from Ashbel Riley, Jr., to George during his travels in Cuba and around New York; and letters from Anna H. Riley to her family from the Utica Female Seminary and while living with her husband in Chicago. Of particular interest are letters, written in the 1840s by George's cousin Caleb Hutton Hammond, in which he relayed family news and commented on social happenings in Rochester. These include his criticisms of several wealthy acquaintances who follow the Graham System (September 13, 1840); a description of a lecture and demonstration by Dr. Reid of Philadelphia, who studied phrenology; and a discussion of a lecture on American Antiquities that claimed that Egyptians must have settled Central America and built pyramids there (February 26, 1841). The majority of the letters spanning 1892-1917 are from Belle Hart ("Aunt Belle") to George Riley. She wrote from hotels in New York City and Rochester; the content is personal in nature.
Visual material includes letters on hotel letterhead that feature engraved depictions of the hotel, and a December 25, 1849, letter from Ashbel Riley, Jr., to George Riley that contains a diagram of his invention for a device that holds writing paper.
The Business Correspondence series (494 items) documents the Rileys' business communications, largely concerning property transactions and debts. Both Ashbel and George invested heavily in land but struggled to pay back debts throughout their lives. The bulk of these papers ranges from 1840 to 1895. In addition to letters requesting repayments for loans, the series contains copies and drafts of outgoing letters from George S. Riley to business partners and debtors, with many sent o S. P. Ely concerning property in Diamond, Utah, and in Michigan.
The Personal Writings Papers series (189 items) is comprised of non-correspondence writings, including notes, speech drafts, and fragments (1841-1908). Included are two bundles of items, which are kept in their original order, entitled "Scribblings & odds & ends -- t. c. in reference written mostly 1841, 2, & 3" and "Temperance Convention" from October 1845. These primarily relate to temperance activities with some material concerning the Seneca Indians.
The Financial Records series (1481 items) consists of receipts and accounts, account books, tax records, insurance records, stocks, and other miscellaneous items related to the Rileys' finances. The bulk of these records dates from between 1850 and 1880. In addition to the family's detailed business accounts, the series conatins a 1844 house expense book.
The Documents series (226 items) consists of legal papers (62 items), real estate papers (131 items), Grand Council of the Iroquois papers (14 items), and temperance-related papers (13 items). The legal papers concern Ashbel and George's financial problems related to land owning and paying taxes. It also contains George's patent certificate for "Improvements in smoke consuming furnaces." The real estate papers document the Riley's land holdings, mostly in upstate New York, consisting of land agreements and details on values. The Grand Council of the Iroquois papers are comprised of documents and letters relating to meetings of the Grand Council between 1842 and 1846. These include a description of a Seneca fort and a burial ground that Timothy Sullivan destroyed during his raids in 1779, a petition to Congress concerning Seneca landholdings, and a heavily edited description of a meeting. The Temperance papers contain documents related to various temperance meetings held in Rochester in 1845.
The Photographs series (1 item) contains a photograph of a bearded man, likely George S. Riley, taken by Notman & Fraser of Toronto, Ontario.
- Newspaper clippings (71 items), mostly from Rochester papers containing topics such as death notices, scientific and philosophical articles, poetry, and news of the day
- Pamphlet (1 item) entitled, "Inquiries, Respecting the History, Present Condition and Future Prospects of the Indian Tribes of the United States" 
- Invitations (9 items) for formal and religious events such as lectures, plays, memorials, weddings, and a piano recital
- Miscellaneous material (10 items), including a voter registration reminder, and a constitution for the Christian Reform Association of Monroe County, New York.