Is the following clause in parentheses an adjective or adverb clause Edgar Allan Poe was an American author (who wrote Gothic and macabre short stories)?

The clause in parentheses, "who wrote Gothic and macabre short stories," is an adjective clause. It provides additional information about the noun "Edgar Allan Poe," describing what kind of author he was. Adjective clauses modify nouns, whereas adverb clauses modify verbs, adjectives, or other adverbs.