The topic—"Literary devices in American poetry"—would be a weak topic because such a topic is extremely vague and not specific enough.
American poetry uses many, MANY literary devices—and many of which are not unique to American poetry alone. Also, "American poetry" in general is too broad of topic.
Mary Shelley uses a multiple narrative in Frankenstein. A multiple narrative (sometimes referred to as an epistolary narrative) uses the voices of multiple characters within the text. Epistolary narratives can also use letters (such as Walton's four letters at the opening of the novel and the letters between the Frankenstein family) to detail parts of the plot and storyline.
