Steal the ground first, then dig it
Brooks proposed that before extending the approaches beyond the second parallel, the trench guard’s outposts be pushed forward gradually, night after night, so that as much ground as possible was already held when the sap started. Gillmore ordered it done. This is how the Federal line crept up on Battery Wagner: a few yards of sand at a time, in the dark.
Major Brooks’ journal, OR I, 28, Pt. 1