Final answer:
The excerpt from Frederick Douglass's autobiography showcases the use of imagery.
Step-by-step explanation:
The most clearly shown element in the excerpt from Frederick Douglass's autobiography is imagery. Imagery refers to the use of descriptive language and sensory details to create a vivid mental image for the reader. In this excerpt, the author describes crawling into a bag and sleeping on a cold, damp, clay floor with his head in and feet out. This description appeals to the reader's senses and helps them envision the harsh conditions of his sleeping arrangement.
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