Hiram Potter was the last Governor of Vandalia and the first Governor of Northern Vandalia. Potter supported the policy of separating Vandalia into two confederations, and it seems likely that his election as governor was based on that support. One of his reasons for favoring separation is reported to be the opportunity for Vandalia to gain an additional five seats in the Senate.
Following the separation into Northern Vandalia and Southern Vandalia in 1877, Galloway, the former capital of Vandalia, became the capital of Northern Vandalia. Potter continued in office as Governor of Northern Vandalia, presumably based on being a resident of the new confederation.
Sobel's sources for Hiram Potter are David Lea's Vandalia in the C.N.A.: A History (Galloway, 1946), and Martin Kleberg's The Politics of Vandalian Separation (New York, 1957).