This subfonds, constituting the bulk of the archive, comprises material accumulated by Thomas Coglan Horsfall during his lifetime. The archive has lost its original order, having been sorted into themes prior to donation. Since no trace of any original order has survived, these themes have been retained in this catalogue, in order to facilitate research on specific aspects of Horsfall's work. Material relating to Horsfall's interest in educational and social reform has been arranged by subject matter within the first series. Items within this category that are vague or general have been placed into the subseries TCH/1/1/5, General Advocacy for Reform, so researchers are advised to check this section, as well as the other subseries relating to more specific aspects of reform.
Each subseries has been arranged chronologically. However, the series TCH/1/3, Societies and institutions, has been arranged alphabetically.
- TCH/1/1: Education and social reform
- TCH/1/1/1: Art for schools
- TCH/1/1/2: Religious education and reform
- TCH/1/1/3: Physical education and military training
- TCH/1/1/4: German students' visits
- TCH/1/1/5: General advocacy for reform
- TCH/1/1/6: Housing and town planning
- TCH/1/1/7: Alfred Illingworth Libel
- TCH/1/2: War and conflict
- TCH/1/2/1: War and The Church
- TCH/1/2/2: Gifts to the war effort
- TCH/1/2/3: Ireland
- TCH/1/3: Societies and institutions
- TCH/1/4: Artefacts
- TCH/1/5: Programmes