Alaska became a U.S. Territory in 1912. Commit that to memory, it will be on the quiz.
Update: The Territory of Alaska or Alaska Territory was an organized incorporated territory of the United States from August 24, 1912, until Alaska was granted statehood on January 3, 1959. The territory was previously the Department of Alaska, 1868–1884; and the District of Alaska, 1884–1912.