The View From Wisconsin

I have done the research, made the inquiries, and it turns out my theory about the naming of Silvernail Road is all wet.

One of the most common reasons for the naming of a particular street or road or highway is for a very obvious reason - it is named for some particular person that either lived on the road, or was otherwise a notable person in the area's history (i.e., they were a former mayor or governor or some other such person).

Conrad and Sylvester Silvernail apparently fit that bill. Though their family originally settled down in Mukwonago, apparently they had a tract of land out between Delafield and Pewaukee/Waukesha that was notable enough that the road that went either to or through their land was known as... Silvernail Road.

And so we have a minor mystery solved: Silvernail Road is named for a person.