Scarce full of regular army private with is Springfield rifle and bayonet.
Unfortunately no photographer information to know where this image was taken, but this is a regular army infantryman wearing his 1872 dress uniform, and holding his Model 1873 Springfield Rifle with bayonet.
The photographer had used some gilt paint to embellish the brass features, thus blurring the regimental designation. The shako would be the indicating factor of being a regular, as well as the rifle, and the buttons on the cuff facing near to the points.
The era for the image is the 70s, and at this time most of the regiments were being sent to the West, after having been stationed in the South during Reconstruction.
A nice image, not commonly found.