The William Edward Foster Family Papers includes correspondence from Foster to family prior to and during the Civil War, letters to/from Foster and his wife, Cora, from the 1870s into the 20th century, a few letters written about Foster, and a collection of letters to and from other family members. In addition, there are family papers consisting of genealogy/family history research, photographs and copies of family members and gravestones, newspaper clippings, pages from a family bible, handwritten fragments of poetry, and other ephemera. Items in the collection range in date from 1800-1931, with many materials undated, but the bulk of the collection is from about 1850-1884.

Most of the letters have donor-provided transcripts in which no wording, spelling, or punctuation has been changed. A transcript has been created by Special Collections staff for one additional letter.