Why was the 54th Massachusetts Regiment famous?

It was an African American unit that was noted for heroism in battle.
It was a Union replacement unit that turned the tide at the Battle of Gettysburg.
It was composed of men under the age of 20.
It was the only integrated unit during the Civil War.

It was an African American unit that was noted for heroism in battle.

The 54th Massachusetts Regiment was famous for being an African American unit that was noted for heroism in battle.