From whom did the US purchase Alaska?

The United States purchased Alaska from the Russian Empire in 1867 for $7.2 million ($2 per acre) through a treaty signed by Secretary of State William H. Seward and Russian Minister to the United States Eduard de Stoeckl. The treaty was ratified by the United States Senate on April 9, 1867, and by Tsar Alexander II on May 14, 1867. The formal transfer of Alaska to the United States took place on October 18, 1867, in Sitka. The purchase of Alaska is often referred to as "Seward's Folly" because many Americans at the time considered the purchase to be a waste of money. However, Alaska has since proven to be a valuable asset to the United States, with its vast natural resources, strategic location, and cultural diversity.