Final answer:
The provided excerpts don't contain enough information to determine the specific city where Mairs was living when she wrote the essay based on her description of "watching the sunset."
Step-by-step explanation:
Mairs' description of an evening "watching the sunset" does not provide a definitive city where she wrote the essay. However, by analyzing the excerpts provided, the descriptions of the surrounding environments in the passages are varied and do not point to one specific city. For example, the references to peacocks on a lawn, a formal doorway with mullioned windows, and the setting sun over a high ridge behind a city suggest different regions and settings. Additionally, there are mentions of iconic locations like Manhattan and the African coast, but these are part of separate passages that do not seem to be related to Mairs' essay. Without more context, it is not possible to accurately determine the city where Mairs was living when she wrote the essay based solely on the phrase "watching the sunset."