The incumbent Governor, Edward Salomon, had ascended to office after the accidental drowning of his predecessor, Louis P. Harvey, in April 1862. He was a former Democrat who had been elected Lieutenant Governor on the Republican Party's Union ticket in 1861. He was not re-nominated by the Republican Party.
^Joint Committee on Legislative Organization, Wisconsin Legislature (2015). Wisconsin Blue Book 2015–2016. Madison, Wisconsin: Wisconsin Department of Administration. pp. 699–701. ISBN978-0-9752820-7-6.