Regimental and Battalion Histories
The Academy Library has a large collection of regimental and battalion histories.
To find a history, follow this link to the library catalogue advanced search. Then, type the name of your mentor's regiment or battalion into the second search field.
Broaden Your Results
For broader results, change the second field drop down from 'Title' to 'Any field'.
This searches variations on the regiment or battalion name, e.g. '2/29' as well as 2/29th'.