Because of the slave issue, Faulk left the Democratic party to support John C. Frémont in 1856 and Abraham Lincoln in 1860.

In August 1866, President Johnson dismissed Newton Edmunds and appointed Faulk as Governor of Dakota Territory.

After arriving at Yankton, Dakota Territory on September 3, 1866, Faulk relieved Edmunds of his duties and served as the interim Governor until officially assuming the office on March 16, 1867.

Because of reports of pine timber and mineral wealth in the Black Hills, Faulk wanted to exclude that area from any future Indian reservation and to open it to white settlement.

Because of his efforts to open the Black Hills to white settlement, Faulk was popular with entrepreneurs and adventurers in Dakota Territory.