Calling all uniform specialists

If you are a Don Troiani-type ACW buff with a goodly reserve of uniform and accoutrements knowledge, here is a controversy you won't want to pass up.

Is the New Hampshire soldier in this monument dressed as a Rebel or as a Spanish-American War infantryman?

A couple of possibilities were missed by the controversialists: (1) a Union uniform with a slouch hat in lieu of kepi (2) An early-war regimental uniform.

What say ye?