Yeah, that's where the Union Arty "set up" during their first assault on Jackson during May of 1863.
BTW, I also worked in downtown JXN during the late 70's (on Congress Street ... one block off Capitol Street).
Since everything had been long paved over, I never thought about relics until the old Lamar Theater was demolished to
make room for "One Jackson Place". They would not let anyone close to the the site, but I'm sure they found many relics.
During the early/mid 80's I worked at the old Employment Security Commission HQ on West Capitol Street ... close to the Zoo.
There were all kind of bullets & shell casings out there.
But all modern.