In September 2006, three nooses were found dangling from a tree at a high school in Louisiana. At a school assembly, a black student had asked the vice principal if he could sit under the same tree – in a traditionally white part of the school yard. Tom Mangold uncovers the truth behind allegations that racism still exists in the Deep South of America. As a black man announces his presidential candidacy, This World investigates how far race relations have progressed since the turbulent 1960s.