Short summary of the story, The Christmas Dance, from Five-Carat Soul?

In the story, The Christmas Dance, a student named Herb Melton seeks information about an all black regiment in World War II from its last two surviving members, a mailman and a retired judge. The mailman, Carlos, tells Herb about the bravery exhibited by their friend Clifford Johns who sacrificed his life for his unit. When they discovered Johns’ body, he had a letter to his wife Lillian in which he promised to take her dancing every year on Christmas Eve. To honor him, Carlos and the judge take Lillian Johns dancing every year in his place.