What kind of literary creation do you think it might be?

Although Washington’s Up From Slavery is primarily a work of non-fiction, it still is a literary creation nonetheless. Please explain for me how it actually represents realism more than anything else. Show me some of the qualities of realism in it.On the other hand, Du Bois’s The Souls of Black Folk seems to be a literary creation somewhat different than Washington’s. What kind of literary creation do you think it might be?