Citing US National Governmnet Record

I am trying to cite The War of the Rebellion: A Compilation of the Official Records of the Union and Confederate Armies using the basic format for books as a starting point and incorporating guidance and examples from EE 11:24-11.25  Some of the unique aspects of this work present some additional challenges and questions.  As a side note, although this work is also included in the U.S. Serial Set which is covered in 13.26-13.40, they were also published as a stand alone work which is what I am trying to cite.

This "work" was published over a period of 21 years (1880-1901) and comprises 69 volumes.  These volumes are comprised of four series with volumes sequentially numbered within each series and with some volumes encompassing several parts:

• Series 1, Volumes 1-53;
• Series 2, Volumes 1-8;
• Series 3, Volumes 1-5;
• Series 4, Volumes 1-3

The title page of each volume states:

Published Under the Direction of The Hon. [Name], Secretary of War, by [Name1], [Name2], [Name3], Board of Publications.  Obviously over the course of 20 years the names change and how to handle this is one of my questions. 

My approach:

Each Series would need to be a separate title/source since the volumes are not numbered sequentially throughout the entire work.

The department/agency would be treated at the author (EE:13.24)

The people noted on the title page would be treated as editors and/or compilers and would be included right after the title (EE; 12.66 & 13.31).  Because the names change over the years, but it is always notes the "Secretary of War", I thought using "Secretary of War, et al." as he editor would be the best approach.

My citations based on above:

Bibliography Entry

United States. War Department. The War of the Rebellion: a Compilation of the Official Records of the Union and Confederate Armies. Series 1, 53 vols. Secretary of War, et al. Washington, D.C. : Government Printing Office, 1880-1901. Digital image. https://babel.hathitrust.org : 2022

Footnote

U.S. War Department, The War of the Rebellion: a Compilation of the Official Records of the Union and Confederate Armies, Series 1, 53 vols., Secretary of War, et al., (Washington D.C., 1897), Series 1, vol. 50, part 2, pp. 410-411, 22 April 1863 letter to Lieut. Col. R. C. Drum from P. Edw. Connor, Brigadier General; digital image, Hathitrust Digital Library (https://babel.hathitrust.org/cgi/pt?id=umn.31951002188670t&view=1up&seq=9&skin=2021) > image 418-19 of 1406.

Short Footnote:

U.S. War Department, The War of the Rebellion: a Compilation of the Official Records of the Union and Confederate Armies, Series 1, vol. 50, part 2, pp. 410-411.

Thanks for any suggestions and guidance,

Curt