The bulk of this collection houses correspondence between Sarah (Probert) Watkins and family and friends living in Ohio, Indiana, and Illinois between 1865 and 1905. Other letters were written to and from George Probert and other members of the Probert family.

The collection is arranged into four topical series:

Series I: Correspondence of Sarah Probert Watkins (1857-1915) houses letters written between Watkins and various (primarily female) family members. These women discuss their daily activities and communicate family and local news. Among the most frequent correspondents are Eliza (Probert) Freeman and Emma Frances Watkins.

Series II: Correspondence of George Probert (1866-1899) and Series III: Correspondence of Other Family Members (1864-1948) house letters written between other members of the Probert family. The majority of George Probert's correspondence discusses business and personal matters.

Series IV: Other Family Papers (1838-1879) houses letters to John Watkins (including a notice of an 1873 reunion of the 19th Ohio Battery) and items documenting Tinnie Watkins' training and certification as a school teacher.