What are the motifs in The River Between Us by Richard Peck?

Consider the past and the present. Racism and prejudice are, in a fundamental way, attitudes defined by past experience, by beliefs and values imparted by those who have gone before. In other words, they are learned behaviors. In the words of the famous, anti-racism anthem from the musical "South Pacific," "You've got to be taught to be afraid / Of those whose skin is a different shade / Or those whose eyes are oddly made / You've got to be carefully taught." With that in mind, then, the first aspect of the book's thematic exploration of past and present is manifest in its second primary theme - the transcendence of prejudice of any sort is a triumph of present over past.