Alaska ( /əˈlæskə/ (help·info)) is the largest state of the United States of America 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 683,478 residents reside within the Anchorage metropolitan area. As of 2007, Alaska remains the least densely populated state of the U.S.
The U.S. Senate approved the purchase of Alaska from the Russian Empire on March 30, 1867, for $7.2 million at two cents per acre, about five cents per hectare. 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" was already introduced in the Russian colonial time, 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.