I placed a jar in Tennessee,
And round it was, upon a hill.
It made the slovenly wilderness
Surround that hill.
Stevens uses this line as a bookend, to provide organization and structure amidst an otherwise oblique writing style. “Tennessee” is repeated at the poem’s close, suggesting the unending relationship between man and nature. 
 Note that “I” speaks on behalf of humankind–not just Stevens. 
 Also, don’t forget the other meaning of the word “jar"—something sudden and unpleasant. When the driver of a car slams the brakes, you could call it "jarring.” We wonder if this jar is going to…jar anything in the poem to come. Maybe upset the natural order of things?
Anecdote of the Jar