Ah, my insane obsession with DC Geography kicks in again...
Everyone has pretty much settled on Kansas as the location of Smallville.
But pre-Crisis? Some folks, including DC, had a different idea.
Check out the map from The New Adventures of Superboy #22 (1981):
Now, Metropolis and Gotham both have sea ports, which makes it rather unlikely for them to be in the midwest.
Indeed, it looks as if that map is intened to closely resemble real-world Atlantic coast geography:
This is consistent with the geography that DC was trying to sell us at the time. The Amazing World of DC Comics #14 (1977) straight-up declared Smallville to be in Maryland.
Somewhere along the way that idea changed, and from the Byrne reboot onward, Smallville has been pretty consistently portrayed as being in Kansas--perhaps because that better fit our preconception as the decent stock of farm folk who would raise a super man, not like those East Coast city slickers and their evil ways.
Plus, no doubt, it suited Byrne, who let both Ma and Pa Kent remain alive, to have Metropolis be farther away, metaphorically and in distance, from where Superman operated. Otherwise, there no reason the Kents wouldn't constantly visit Clark (and vice versa) with that cozy distance.
That issue of Superboy also included a map of the entire town of Smallville...click to embiggen:
Scott Snyder had Superman say that Smallville had a population of 36,000 (!), that's an awful lot of people living in each house...