With the gun being manufacture in March of 1863 in Massachusettes it most certainly didn't start out life as a confederate weapon. Since it was found in Arkansas I would look at Union units that were armed with the model 1841 Howitzers. Mostly these guns were religated to the reserve artillery which rarely saw action therefore would not have been lost.

However, in Arkansas, Cavalry Units from both sides used these guns. The most famous user of the model 1841 was again the 5th Kansas cavalry and again they lost 2 and maybe three according to reports of guns captured by the Confederates at Marks Mill April 1864. It is possible that this is one of those guns being used by Confederate Cavalry in Price's Missouri raid in late 1864.

While there may be other explainations that is the largest number of these guns being "lost" during the War that I know of. The remaining guns of the 5th Kansas Cavalry after the war were transferred to battery "H" out the 2nd US Colored Battery of light artillery at Pine Bluff. What happened to those guns are unknown.