It literally reflects the famous 1770 engraving of the Massacre by Henry Pelham with the soldiers lined up and firing together (on the left instead of the right) and the spires behind. But this portrayal emphasizes the civilian reaction to the soldiers, with the three lamenting women.
Johnson put Crispus Attucks alone at the center, gave him a Christ-like beard and pose, and named the painting after him. That reflects the importance of his memory in the African-American struggle for rights.
This painting is now part of the Smithsonian Institution’s collection.