Answer :
"d) the Battle at Fort Wagner" is the most widely known effort by African Americans in the Civil War, because an African American regiment offered to lead the assault against Confederates.
The correct answer is option d) "The Battle at Fort Wagner". On July 18, 1863 during American Civil War, the 54th Massachusetts Volunteer Infantry, a Union regiment of free African American men, began their assault on Fort Wagner. Even though the assault resulted in 116 men killed along with the Colonel of the regimen, the soldiers shown great bravery and carried the Union flag until the last moment.