Set shortly after the American Civil War, ''Buck and the Preacher'' follows a former soldier named Buck (Sidney Poitier) as he leads wagon trains of African Americans from Louisiana west to the unsettled territories of Kansas. In order to ensure safe passage and food for his company, Buck has, for one, learned to negotiate with the Native Americans in the area. He pays them, and in turn they allow him to kill American bison and pass through their land with specific time constraints. However, the natives are not the only factor to deal with.