This study aims to explore Natasha Trethewey’s work, focusing mainly on her Pulitzer-Prize winning volume Native Guard. In this volume, Trethewey tried to restore the hidden and forgotten part of American history through poems of mourning, photo texts, and a personal journal. This study concentrates on the poems concerning both the death of Trethewey’s mother, and her guilt and mourning. Her interminable mourning for her mother expanded and continued to recollect the hidden and forgotten history of the African-American Native Guard during the Civil War. This study suggests that Trethewey linked some photo texts as a reminder of hidden moments or hidden realities, to the historical facts in American society. In some interviews, Trethewey mentioned that a certain moment or a certain element in a photo―Barth’s punctum―could attach with and extend to an imagined world. As for Trethewey, the punctum of a photo could play a significant role in excavating hidden realities. This study further examines the journal of an imagined African-American soldier during the Civil War, which was constructed as a sonnet cycle. Through this personal journal, narratives can be traced of the community neglected, hidden, and forgotten by American official history. Moreover, this study emphasizes that Trethewey built a “lyrical monument” or “a monument in words” both for her mother and for African-American soldiers through the book, Native Guard.