Hendrickson entered politics in 1946, when, upon the urging of his friends, he was elected
mayor of Juneau. In this role, he helped the city gain the power to levy and use sales tax, which had not been enforced before, leading to a lack of funding for Juneau. Because of the collection of this tax, Hendrickson developed Juneau, leading the city to become the first city in Alaska to be fully paved. He served as Mayor of Juneau until 1953. While serving in this role, he was also a member of the territorial
House of Representatives from 1948 to 1953. In 1953, Hendrickson was appointed Secretary of Alaska Territory (equivalent to
Lieutenant Governor of Alaska today) by President
Dwight D. Eisenhower, under Governor
Frank Heintzleman. He held this office until statehood, serving as acting governor twice, once in 1957, and again from 1958 to 1959. Hendrickson was the first Alaska governor born in the territory. After statehood Hendrickson served on several government commissions, as well as chairing the
Interior Department's Alaska Field Committee, and the Juneau office of the
Bureau of Land Management. He retired due to poor eyesight, in 1965. ==Later life==