The fonds consists of holograph correspondence written primarily to his mother from the trenches and war front in Europe, together with a typescript transcription of the letters; a photograph of Macgowan with (apparently) two members of his battalion; programme for a Brussels Ball; clippings; and 11 maps used by Macgowan to direct his troops in battle. Also included are aerial photographs of three regions of north-west France together with a map of north-west France (Denain region). Some of the photographs have holograph additions to them, largely for the purpose of identification of towns or other significant features.

The fonds consists of 2 microfilms of H/Capt. Rev. R. L. Seaborn's diary.