Army List and Directory, 1 January 1928: the entry for Herbert S. Clarkson at the Command and General Staff School, Leavenworth.
Image · dated 1 January 1928 · source: U.S. War Department publication (Internet Archive scan); armylistdirector1928unit.

How it is shown: Complete page as supplied; no crop, no retouch, no search highlight.
Keep in mind: Confirmed as printed.