The Chicago Mercantile Battery was organized in 1862 by a group of prominent Chicago merchants. As part of Maj. Gen. John McClernand's 13th Corps, the battery participated in the long and arduous Vicksburg campaign. The artillerists performed well everywhere they were tested, including Chickasaw Bluffs, Port Gibson, Champion Hill, Big Black River, and the siege against Vicksburg. Ancillary operations included the reduction of Arkansas Post, the capture...