We identify this percussion cone in barrel altered Whitney Model 1816 U.S. musket as a Nashville Arsenal product based on the fact that, unlike other arsenal alterations, the pan cavity is not filled so it is flush with the top of the lock. For further information on this circa late 1860/early 1861 alteration see pages 16 and 17 of ""American Military Shoulder Arms, Vol. III"" by George D. Moller. This musket also has the name ""H.A. Hills"" stamped on the sideplate. The 42"" round 69 caliber has a very good smooth bore. The barrel has a smooth brown patina with light pitting in the bolster area. The inspection marks are JM/P which are followed by MS (Mississippi). The top of the breech is stamped 16 and the tang is dated 1835. The lock, which is bright mixed with brown, has US over crossed arrow and branch over E. WHITNEY at the center and NEW/HAVEN/1835 at the tail. The iron furniture has a smooth brown patina with the exception of the rear band which has medium roughness.  The buttplate tang, in addition to the US, is marked 39/39. The stock is very good with minor use dents and dings, a visible cartouche outline, and no cracks or chips. The ramrod and swivels are present. The action functions correctly. This musket needs further research. It's a nice example of a Southern arsenal Belgian alteration and comes with the added benefit of the Mississippi mark on the barrel and H.A. Hills on the sideplate. Who knows what you'll find! We believe this is most likely a Confederate used musket.