14. Fort Wagner’s defenses were formidable from both land and sea
Although initially constructed as a battery to protect the southern approaches to Charleston Harbor, which wound between the islands, Fort Wagner was a powerful obstacle to Gillmore’s plans to take Charleston. Its parapets were built of sand, reinforced with palmetto logs, which allowed them to absorb shot rather than repel it. They towered 30 feet over the beach below, and fourteen heavy guns were mounted behind the walls, offering a deadly reception to approach by water. The swamp to the west of the fort was all but impassable, troops mired in it would be exposed to devastating fire. The only side approachable by land was protected with a moat.
The moat was a ditch, five feet deep and ten feet wide, itself protected with sharpened stakes made of palmetto. Fort Wagner also contained a bombproof, covered with a beamed ceiling under ten feet of sand, and capable of holding up to one thousand men. Unlike Fort Pulaski, which had been reduced under the bombardment of rifled guns, the construction of Fort Wagner was such that heavy bombardment simply did less damage to the fortress. General Strong was ordered to resume his assault on the Confederate fortification, after additional troops were sent to reinforce his brigade. One of the units sent was the 54th Massachusetts, only two days after their baptism of fire on James Island.