After the Civil War he became a congressman and then resigned to run for Governor of Wisconsin, an election he won. His most noted act during his governorship was when he sent the National Guard into Milwaukee to keep the peace during the Great May Labor Strikes of 1886. The strikers had shut down every business in the city except the Bay View Rolling Mills. The guardsmen's orders were that if the strikers were to enter the Mills that they should shoot to kill. But when the captain received the order it had a different meaning and he ordered his men to pick out a man and shoot to kill when the order is given. Several people were killed and Governor Rusk took the majority of the blame.
In 1889 he resigned his governorship and accepted a cabinet position with the Benjamin Harrison administration.