Thinking thinking of those scenes in the movie, I was curious about how that battle really unfolded.
So I looked it up and according to what I found, it looks like the Union Army marched in an arrow kill zone right toward the one part of the fort that had howitzers and carronades. Predictably, the Union troops were torn to pieces.
Surely, I'm missing a lot of other details.
Link to a map -- https://www.civilwar.org/learn/maps/assault-fort-wagner
If you're asking, 'Then how should they have done it?', from reading about successful battles of other forts or installations, it's normally a good idea to attack from multiple points simultaneously.
In this case, why didn't they also attack rom the north?
Lastly, perhaps this is a question about the bigger issue of Naval Gunnery at the time, but I can't help but wonder why the naval bombardment of a fort from such a close proximity was so ineffective.
Furthermore, as the soldiers were marching toward the Union Fort couldn't the ships have been firing into the Confederates, using grape and canister?
Thanks in advance.
The assault at Fort Wagner spearheaded by the 54th Massachusetts faced a problem that often plagued armies till the end of the First World War: its success depended on a preceding, lengthy artillery barrage, which was ineffective.
The Union forces were under the command of Brigadier General Quincy Gillmore. Gillmore was an engineer and an advocate of rifled guns on Navy ships, and during the siege of Fort Polaski earlier in the war, Gillmore used these rifled guns to great effect, breaching the fort's stone walls and forcing its surrender.
Gillmore hoped for a similar outcome on the assault of Fort Wagner. The fort was bombarded by Navy monitors and field artillery for eight hours prior to the start of the actual assault. It is clear that Gillmore was relying on the rifled guns to render the fort largely defenselesss before ordering the infantry forward.
However, Gillmore did not take into account that Fort Wagner's walls were not made of stone, but of earth and sandbags. The effect of artillery on a sandbag fort, as Shelby Foote put it in Ken Burn's Civil War, was "like punching a pillow." Gillmore's bombardment of Wagner was ineffective, killing only a few Confederate soldiers and failing to neutralize the fort's big guns.
Thus, the 54th Massachusetts attacked expecting to face no howitzers and a greatly reduced garrison. They encountered neither, and the rest, as they say, is history.
As for your last question--
Furthermore, as the soldiers were marching toward the Union Fort couldn't the ships have been firing into the Confederates, using grape and canister?
These sorts of tactics would not begin to take shape until the middle of the First World War, when the creeping barrage was first introduced. This required extensive planning with timetables and fairly accurate artillery to avoid killing one's own troops. Artillery tactics simply had not advanced to such a point by the time of Fort Wagner, largely because guns were still quite inaccurate and liable to simply slaughter men on both sides.
sources:
Where Death and Glory Meet: Colonel Robert Gould Shaw and the 54th Massachusetts Infantry by Russell Duncan
World War I Battlefield Artillery Tactics by Dale Clarke