Final answer:
In Charles W. Chesnutt's The Goophered Grapevine, the significant and socially challenging idea is the critique of post-Civil War racial dynamics and exploitation of African Americans, which were contentious issues during the era.
Step-by-step explanation:
The concept in The Goophered Grapevine that was particularly significant and socially challenging during the time it was written is the depiction of the Reconstruction era South and the complex racial dynamics that were prevalent post-Civil War. The story, written by Charles W. Chesnutt, an African American writer, confronts the legacy of slavery and the exploitation of African Americans in a subtle yet profound way, reflecting the political and social challenges of the era.
Chesnutt uses folkloric elements and dialect to explore themes of racial identity, the power of storytelling, and the exploitation of black labor. These themes were sensitive and contentious due to the deeply entrenched racial divisions and the recent end of slavery. The story not only entertains but also serves as a critique of the social order of the South, challenging its readers, who were likely of the educated and financially secure middle- or upper-class, to come to terms with the realities of the racial politics of their time.