For a close view of siege warfare, walk up into the fort, to the
artillery piece at the right of the avenue. From the ridge 150 yards
away, Union cannon, which are trained on the fort, blasted the
Confederate defenders continuously. During the assault of May 22,
Grant's infantry reached the wall of the fort. The two black markers in
front of the cannon and just below it indicate where colorbearers
planted their flags, almost at the top of the wall, before the assault
was broken and driven back.