Maps can often unlock genealogy mysteries by showing connections and relationships that might not be apparent in written records. For instance, who lives close to who, how far it is from here to there, etc.
There used to be a good map store on Delaware Street north of St. Clair that carried lots of Indianapolis and Indiana maps of various kinds. The physical store closed some time ago, but it still operates primarily online (doesn't everything any more?). You might want to check out the Osyssey Map Store site if you are in the market for local historical maps.
[Disclaimer: I have no personal or financial interest in this company.]