Why is the Louise Kendricks so important to Marguerite?

The store is crammed with people listening to a Joe Louis fight on the radio; he is fighting a white man, and of course they all support Joe Louis because he is black. His victory means everything to them; they pin their hopes for dignity and equality on it, and are very happy when Louis does win the fight. "Joe Louis had proved that we were the strongest people in the world" by winning the fight, Angelou said; his victory gives hope to the people of Stamps, though whether it will really change anything is unclear.