My family owns a bunch of property along the Big Black River, just 'up the road' from the Grand Gulf Military museum. They have a remnant of one of the 6th MS's regimental flag on display.
FYI, on family property (Thompson's Ridge) I have been "relic'ing" on the site of 3 Confederate artillery batteries. The 3 pieces had to be abandoned (not enough horses to pull 'em) when Grant came ashore just south of there. I killed my first deer on that ridge a long, long time ago, never knowing what a treasure was there. You can still see the 'cutouts' of the earthen walls about 50 yards apart from each other and the notches in the dirt where the barrels extended thru the earthworks.