Natasha Trethewey's muscular, luminous poems explore the complex memory of the American South--history that belongs to all Americans. The sequence forming the spine of the collection follows the ''Native Guard'', one of the first black regiments mustered into service in the Civil War. In Trethewey's hometown of Gulfport, Mississippi, a plaque honors Confederate POWs, but there is no memorial to these vanguard Union soldiers. ''Native Guard'' is both...