Alaska (i /əˈlæskə/) is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait. Approximately half of Alaska's 698,473 residents live within the Anchorage metropolitan area. As of 2009, Alaska remains the least densely populated state of the U.S.
Alaska was purchased from the Russian Empire on March 30, 1867, for $7.2 million ($113 million in todays dollars) at about two cents per acre ($4.74/km²). The land went through several administrative changes before becoming an organized territory on May 11, 1912, and the 49th state of the U.S. on January 3, 1959.
The name "Alaska" (Аляска) was already introduced in the Russian colonial period, when it was used only for the peninsula and is derived from the Aleut alaxsxaq, meaning "the mainland" or more literally, "the object towards which the action of the sea is directed". It is also known as Alyeska, the "great land", an Aleut word derived from the same root.