He could have served in the Banana Wars, the Orient and many a "clime and place."
It was a time of transition for the Corps, in uniform and in purpose. He's got the new 1903 Springfield rifle, but hasn't switched over to the new combat boots or the "Montana Peak" campaign cover-- he's too salty for that, yet... soon enough he'll be training for expedition to France, but now he's still using the old ways of the Marine rifleman.
Here is the original build up of the sculpture, seen from skeletal armature all the way through to its current near-finish state:
The "Ecorche" figure, fully fleshed out:
Now for his clothing issue:
Here's the original maquette I made for the piece (it's about 8" tall):