Pittsfield could be Pittsfield, Illinois. The regiment was organized in September 1861, and two companies were at Alton, Illinois until the following March. Coincides with the time period McCoy enlisted. Pittsfield is 70 miles from Alton and just a stones throw from Missouri. With Illinois regiments having filled up fairly fast, there were a lot of troops signing on with Missouri units during 1861 and it's possible the Missouri regiment was sending recruiters out into the Illinois countryside to sweep up the overflow....