Reference for electoral history
When I was looking into the disambiguation of Roger Johnson, I came across the following reference, which I used to cite the electoral results of that election:

The section "Electoral history" was unreferenced until I added this; I suspect that, if someone wants to take the time, this book will serve as a reference for all of these electoral results.

As an aside, this section wikilinks most of Jefferson's opponents, but as a rule, these unsuccessful candidates are not sufficiently notable for an Wikipedia article, and should probably be unlinked (at least one, Jon Johnson, is a mislink to an unrelated article).