That constituent of the archive under the reference D1295 comprises around 700 documents, around 1900-1960, and falls into three groups.
Firstly, there are papers relating to Spender's retirement from the Army in 1913 when he was compelled to do so for his action in signing the Ulster Covenant.
Secondly, there is material pertaining to his activities between 1914 and 1919, as an administrator in the Ulster Volunteer Force during the period of the organised gun-running at Larne, Co. Antrim, and relating to his resumed military career after August 1914, initially with the 36th (Ulster) Division in the 1st World War and later as Staff Officer at GHQ.
Thirdly, there are papers relating to his career in Northern Ireland from 1921 to 1944, comprising almost entirely of letters and memoranda. Notable correspondents include Lord Craigavon, Lord Carson and General Gough with incidental letters from a very wide range of public figures.