Final answer:
The story "Half of a Yellow Sun" is set in Nigeria during the Nigerian Civil War, specifically in the southeastern region, where the Republic of Biafra attempted to secede.
Step-by-step explanation:
The story "Half of a Yellow Sun" (2006) by Chimamanda Ngozi Adichie is set during the Nigerian Civil War which took place from 1967 to 1970. Specifically, the novel is located in Nigeria, primarily in the southeastern part, which attempted to secede as the Republic of Biafra. Adichie constructs a narrative that follows the lives and struggles of various characters during this tumultuous period, highlighting the impact of the tragic conflict on personal relationships and identities. The enhancement of the story through its setting showcases the author's connection to the country, as Adichie herself grew up in Nigeria.