They tried to enlist into the confederacy but the pro-confederate Governor refused to give them military assignments and the Louisiana legislature passed a law requiring that units be whites-only and the unit was disbanded. When New Orleans was occupied by Union forces, 10% of them went and fought for the United States.
The one thing I learned from studying black soldiers in the Civil War, and after meeting the descendant of one of the member of the 54th Massachusetts, who had retired as a Colonel from the U.S. Army, was that in every war, the black soldier had to prove himself over and over. Before joining the Army in WWII, he had joined the black parachute group The Triple Nickel (555). They trained every day to jump out of planes. He said they got to good at jumping out of planes, that they could put a chalk mark on the side of the plane as they went out. He got extremely frustrated because the government wouldn’t let them go overseas, and instead used them to fight fires in the west. He left that group and joined a black Army unit and fought in Italy. He was also in Korea at Heartbreak Ridge. His grandfather was the first black soldier enlisted in the 54th in Boston in 1863. He left school to enlist, and lied about his age. He was also the last survivor of the 54th.