In order to be able to list five separate illustrations, break down the wide response of "racial conflicts within the story" into some of the separate items included under the topic of racial conflicts.
It is a historical fact that separate but equal facilities were the legal requirement in the South in that time period, but that the equality was frequently lacking. This could be illustrated by referring to housing, facilities within specific homes (toilets), stores (consider the quality and variety of foods available at the different grocery stores), and transportation.
You could look at employment trends in the South in the 1960's. What percentage of the white population worked as domestic help in comparison with the percentage of the black population that did so? You could also reference Skeeter's struggle to be accepted as a young, female writer of serious news as opposed to household hints.
Specific historical events are cited within The Help. These could also be referenced to establish the link to history.