Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, bordering Yukon Territory and British Columbia, Canada, to the east and southeast, respectively; the Arctic Ocean to the north; and the Pacific Ocean to the west and south. It shares a maritime border with Russia across the Bering Strait, with the closest point between the two being between the Diomedes, a pair of islands two miles apart; Alaska owns Little Diomede, while Russia owns Big Diomede. Alaska is the third least populous and the least densely populated of the 50 United States. Its capital is Juneau and its largest city is Anchorage. Approximately half of Alaska's 700,000+ residents live within the Anchorage metropolitan area.
Alaska was purchased by the U.S. government from Russia on March 30, 1867, for $7.2 million ($120 million when adjusted for inflation) at approximately two cents per acre ($4.74/square kilometers). The land went through several administrative changes before becoming an organized (or incorporated) territory on May 11, 1912, and the 49th state of the U.S. on January 3, 1959.
The name "Alaska" (Russian: Аляска) was already introduced in the Russian colonial period, when it was used only for the peninsula, and is derived from the Unangax (Aleut) word "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 Unangax word derived from the same root.
Alaska has been inhabited for thousands of years, and is widely believed to be the point through which humans first entered the Americas. It's believed that the Na-Dene peoples--the Athabascans, Tlingit and Eyak peoples--were among the first humans to arrive in Alaska, sometime close to the end of the last ice age, and have maintained a presence there ever since. To this day, Alaska has the highest percentage of indigenous residents of any US state.