In 2000, the United States census allowed respondents for the first time to tick a box marked "African American" in the race category. The new option marked official recognition of a term that had been gaining currency for some decades. Africa has always played a role in black identity, but it was in the tumultuous period between the two world wars that black Americans first began to embrace a modern African American identity.

Following the great migration of black southerners to northern cities after World War I, the search for roots and for meaningful affiliations became subjects...