Like much of A. R. Ammons's poetry, "The City Limits" explores the uneasy relationship between modern civilization and the natural world. The images that Ammons uses in this poem, such as his consideration of the sound of "birds' bones" or of the "glow-blue" of the bodies of flies, make readers aware of the subtle things in the natural world that ordinarily would go unnoticed. He also draws readers' attention to dark, fearsome, and unpleasant aspects of the world around them, such as the "guts of natural slaughter" that flies feed on and the "dark work of the deepest cells," an allusion to cancer. It is typical of Ammons's poetry that he is able to show the duality of the way that humans view nature. After making his readers uncomfortable, Ammons ends by making a convincing case that understanding can make fear of nature "calmly turn to praise."

This poem was first published in 1971, when Ammons's reputation as a major American poet was already established. It is available in his Collected Poems, 1951-1971. For the following thirty years, before his death in 2001, Ammons continued to be an innovator, changing styles and producing a varied legacy of poems ranging from book-length to just a few lines long. Throughout the last half of the twentieth century, he was considered to be a central figure among the growing number of poets who embrace the spiritual aspects of science and nature.