Short answers, pulled from the story.
The Second Battle of Fort Wagner was fought on the 18th of July, 1863, during the American Civil War. The assault lasted from 7:45 p.m. until approximately 10:00 p.m. It took place one week after the First Battle of Fort Wagner on July 10-11.
Colonel Robert Gould Shaw commanded the 54th Massachusetts Infantry at the Second Battle of Fort Wagner. Shaw was killed upon the parapet early in the assault. He was buried alongside two of his captains, Russel and Simpkins, in a single grave.
Union losses totaled roughly 1,515 killed, captured, or wounded, though General Hagood reported burying 800 bodies in mass graves in front of the fort. Confederate casualties numbered 174. Of the 54th Massachusetts alone, only 315 men remained after the battle.
William Carney was an African-American sergeant with the 54th Massachusetts Infantry. He recovered the regiment's United States flag during the assault on Fort Wagner and returned it to Union lines. He is considered the first Black recipient of the Medal of Honor for that act.
Lincoln issued General Order 252 halting all prisoner exchanges after Black Union soldiers captured at Fort Wagner were not exchanged alongside their white comrades. The Confederate Congress had passed a law in May 1863 excluding Black soldiers and their white officers from exchange, prompting Lincoln's response. The policy is often wrongly attributed to General Grant.
The Confederates abandoned Fort Wagner on the 7th of September, 1863, after resisting 60 days of bombardment. The fort was deemed untenable due to continuous Union shelling, a lack of provisions, and the close proximity of Union siege trenches.