The group dedicated its new painting in honor of the late Octavius V. Catto.
The civil rights activist appears on the side of the Universal Institute Charter School in South Philadelphia, the neighborhood where he lived and died.
Catto was only 32 years old when he was assassinated on South Street in 1871, after he pushed for voting rights for black citizens.
The unveiling of this new mural Tuesday brought out various officials, including Mayor Jim Kenney.