Ever since the disastrous attack on July 18, the Federals had worked to close the distance between their trenches and the ditch in front of Battery Wagner. By a few feet here and yards there, they had advanced a siege line, placed heavy guns, and buttressed the trenches to allow staging an assault force. After seizing the “ridge” in late August, the Federals held, waiting on the moon and stacking the deck, prior to making that last 200 yard dash. Now, 150 years ago today (September 5, 1863), they were ready to make that push. From Major Thomas Brooks’ journal:
This morning the long-expected, and, by the sappers, anxiously hoped for, bombardment of Wagner by all the land batteries and the Ironsides began, and with it ended all the difficulties in sapping against the work, for the enemy’s fire, sharpshooters and all, is completely subdued, and his distant batteries dare not fire at our advance for fear of injuring their friends in the fort.
In the past two and one-half days, at considerable sacrifice, not more than 25 yards of sap have been executed, and it, from its direction, brought us no nearer the fort. To-day more than 150 yards, most of it by the flying sap, have been built without loss of life. The head of the sap is now opposite the ditch of Wagner; from it fragments of shell can be easily thrown by hand into the work.
The trace of the approach executed to-day is a succession of short zigzags made necessary by the narrow front. Captain [Joseph] Walker was in charge of this work.
Looking to Brooks’ map, here’s the measure of that advance:
The advancing trenches continued the zig-zag arrangement of boyaux, offering no flank openings to either Battery Wagner or James Island. The trenches followed the same basic profile as those constructed since the fourth parallel. Substantial amounts of excavated sand formed the parapet facing the Confederates (see profile on line w-w’ from the map).
To the left side of the first turn of the boyaux, the Federals constructed a rifle trench (seen as line u-u’ on the map):
Nothing more elaborate than a step for the sharpshooters when drawing a bead on their opposite numbers in Battery Wagner.
On the other side of the line, Colonel Lawrence Keitt, commanding the Confederate garrison on Morris Island, recorded:
The dawning revealed a United States flag planted on the enemy’s work, 300 to 400 yards in front, this morning, and their main line strengthened, with probably a small advancement of the parallel which they have to run from about the termination of their main approach. Our riflemen opened early, and a field piece fired 2 shots, out the enemy opened slowly just before 5 with large Parrott guns, first at flank curtain and then at center curtain, with a few shots at the elevated points used by our sharpshooters. The Ironsides soon drew up to about 1,500 yards at, say, 5.20 a.m.; opened fire rapidly. I ordered one-fourth the infantry to remain on the lines, balance to seek shelter in the bomb-proof and passages.
Federal fire, early in the day, had effectively silenced the Confederate defenders. Furthermore, the rain of shells caused several casualties and made considerable damage to the traverses and other structures. Normally the Confederates would wait for night and repair the damage. But now the Federals were too close for comfort and mortar fire made long stays outside the bombproofs unhealthy. Later in the day, Keitt sent a desperate message to Fort Johnson:
I had about 900, and not 1,400, men. About 100 of these to-day were killed and wounded. The parapet of salient is badly breached. The whole fort is much weakened. A repetition to-morrow of today’s fire will make the fort almost a ruin. The mortar fire is still very heavy and fatal, and no important work can be done.
Is it desirable to sacrifice the garrison? To continue to hold it is to do so. Captain [Thomas B.] Lee, the engineer, has read this and agrees. Act promptly and answer at once.
As the clock ticked past midnight on September 5, 1863, the Federals were within 50 yards of Battery Wagner. They had not stood that close to the works since the night of July 18, and with heavy casualties to show for the effort. In the weeks since that failed assault, the use of shovels instead of the musket had closed the 1,300 yards to Battery Wagner.
(Citations from OR, Series I, Volume 28, Part I, Serial 46, pages 300 and 481-2.)