 Complete the following phrase:  During the Battle of Pea Ridge in March 1862, a Confederate unit, Landis Missouri Battery was armed with four guns, two of which were 24-pounder howitzers. At the Battle of Antietam on 17 September 1862, the Confederate Army of Northern Virginia employed four 24-pounder howitzers. Two were part of James Reillys six gun Rowan North Carolina Battery and two were in George V. Moodys four gun Madison Louisiana Battery. The Union Army of the Potomac employed none at Antietam, but at the 