Of 'course' the War Department produced Regulations, Circulars, Directives, and all manner of documents and manuals - and they've done so since there was an American military.
I have an extensive reference library full of originals, and many of the titles are also in reprint form.
During the era, not 'that' many were actually illiterate - and unlike today - most everyone 'wanted' to learn and to better their knowledge, since they knew that their fortunes and conditions would improve markedly.
Folks 'read', back then - and while some of them may've read slowly and puzzled out the meanings - they were committed to the learning process.
You're looking for those references on the wrong Forum - try 'The Barracks', where the guys in the Grand Army of the Frontier cite them often...
While I've supplied my share of references for the GAF - I don't have to do much of that here on the 'Historical Society' forum, since that sort of thing has very little relevance to folks doing a civilian Impression, but you'll see all manner of cited references if you just look.
Vaya,
Scouts Out!