Major Carteret, though dressed in brown linen, had thrown off his coat for greater comfort. . . . Long ago, while yet a mere boy in years, he had come back from Appomattox to find his family, one of the oldest and proudest in the state, hopelessly impoverished by the war,—even their ancestral home swallowed up in the common ruin. Literary era: romantism or realism

Charles W. Chestnutt's historical but yet fictional novel "The Marrow of Tradition" was based on the Wilmington Insurrection of 1898. This event was also a representation of the rise of the white supremacist movement that played a huge role in the 'race riots' that overtook Wilmington in North Carolina.

The passage that is given in the question describes just how exactly the condition of Major Carteret's childhood home was. The author describes the place as "one of the oldest and proudest in the state, hopelessly impoverished by the war,—even their ancestral home swallowed up in the common ruin", giving it a realistic and relatable image of the place. This work of literature was from the realism era, where things and events are written about and describe just how they are. There are no sugar-coating or use of 'better' words to describe the events or things like the romantics do. Romanticism (early 1800s) believed in the presentation of things in a more refined way, making their appearance look more enticing. Whereas Realism (late 1800s) is the exact opposite of it. It denounces Romanticism as a whole and gave the details as how they are in reality. Thus, this novel by Chestnutt is from the Realism era of literature.