The abolition of slavery after the Civil War is a familiar story, as is the civil rights revolution that transformed the nation after World War II. But the century in between remains a mystery: if emancipation sparked ''a new birth of freedom'' in Lincoln''s America, why was it necessary to march in Martin Luther King, Jr.''s America? Gates uncovers the roots of structural racism in our own time, while showing how African-Americans after slavery combatted it by articulating a vision of a ''New Negro'' to force the nation to recognise their humanity and unique contributions to the United States.