This largest series includes correspondence, wills, biographical information, genealogical information, and some financial and legal documents created by the descendants of John Rodger, the Rodgers family, and the families this group married into, such as the Davidsons, Grahams, Irelands, and Letchers. The most prominent correspondents are three of Aleri and Mary Davidson Rodgers' eleven children: Andrew Rodgers Jr. (1818-1847), Isabel Ireland Rodgers (1830-1912), and Calvin Melancthon (C.M.) Rodgers (1835-1906).

Andrew Rodgers, Jr. kept an overland journal while travelling on the Oregon Trail. He also wrote to many of his family about his experiences living with the Whitmans in Walla Walla. He was killed in the Whitman Massacre in 1847. Isabel Ireland Rodgers, who was named after her grandmother, was the genealogist of the family and wrote many distant relatives inquiring about family history. She also collected clippings on the Whitman massacre and wrote to various people about it, including author Myron Eells. Her notes and recollections are important documents of family history and anecdotal information. Isabel Ireland Rodgers graduated from the "Female Collegiate Department" of Knox College in Galesburg, Illinois in 1857, and her diploma is in the collection. C.M. Rodgers was a farmer and politician, who held several public offices, most importantly in the Illinois State Legislature. His correspondence to and from his wife during the years he was away is an interesting collection of letters detailing daily life on the farm and in Congress. C.M.'s business papers deal mostly with land claims, loans, and cattle and crops.