In the following essay excerpt, Costello describes "The City Limits" as an "eloquent example" of Ammons's mastery of poetic technique.

Ammons will return to the stance of the pilgrim throughout his career, but beginning with his second book, Expressions of Sea Level, a different stance begins to emerge, one relatively impersonal, comprehensive, and didactic. Where the medium of the pilgrim poet is ritual gesture, the medium of the sage is abstract proposition and example. The revelation of pattern dominates here over the articulation of self. Problems of identity fall away and the self becomes a node of consciousness through which the shape of the world reveals itself. Where nature in the pilgrim phase is variously the ally or antagonist to the poet's will, here it is the embodiment of dynamic design, often articulated in abstract titles. Critics have emphasized Ammons's interest in "ecological naturalism," and certainly the...