I was recently in Scranton (home of, among other things, Dunder-Mifflin), and saw the large sign proclaiming Scranton as the Electric City. It is called this due to being one of the first electrified cities. Buffalo, also one of the first cities to have electric lighting, has the nickname the City of Light.
This all got me thinking: what are the nicknames of other cities? Here are Wikipedia’s list of city nicknames and list of American city nicknames. Both of these are large collections, although curiously, neither contains the nicknames I just mentioned (although presumably, being Wikipedia, this can be easily rectified). The list of city nicknames does have a great subset of agricultural and industrial capital nicknames though. For example, the Collar City (Troy, NY), Indoor Foliage Capital of the World (Apopka, FL), Horseradish Capital of the World (Tulelake, CA).