Ken:

Some 40 or 50 thousand M1822s and M1842 .69 caliber smoothbores were refurbished and rifled by the US Ordnance Department between 1855 and 1861. The vast majority of these wound up in Federal hands during the War, since the Confederates were initiaally armed out of the local Federal arsenals, and musket modernization did not become a big issue among Southern governors or legislatures until the actual secession crisis late in 1860. The smoothbores taken out of the Little Rock Arsenal were M1822s (5700) and about 250 M1842s.

Tom