Alaska Purchase, (1867), acquisition by the United States from Russia of 586,412 square miles (1,518,800 square km) of land at the northwestern tip of the North American continent, comprising the current U.S. state of Alaska.

Russia had offered to sell its North American territory to the United States on several occasions, but the outbreak of the American Civil War in 1861 led to the postponement of discussions. In December 1866, a year after the war’s conclusion, Baron Eduard de Stoeckl, Russian minister to the United States, was instructed by Emperor Alexander II to open negotiations for its sale. The cost and logistical difficulties of supplying the territory had made it an economic liability to the Russians, who were additionally struggling with debt accrued during the disastrous Crimean War (1853–56). Though Russian interactions with the native Aleut people had been largely peaceful, the Tlingit tribes were more restive, leading to sporadic episodes of violence and the interruption of provisions. Political forces in Russia increasingly looked instead toward Asian expansion and—in light of the American philosophy of Manifest Destiny and increased competition from the British Hudson’s Bay Company, which leased a southern portion of the territory—viewed the eventual control of the territory by the United States as inevitable and perhaps beneficial.

Stoeckl approached William Henry Seward, secretary of state under Presidents Abraham Lincoln and Andrew Johnson, through an intermediary, journalist and politician Thurlow Weed. (Seward, an advocate of U.S. expansionism, had long desired Alaska.) The two statesmen began private discussions on March 11, 1867; Stoeckl remained coy about the sale until Seward expressed interest. On March 29, 1867, Stoeckl and Seward completed the draft of a treaty ceding Russian North America to the United States, and the treaty was signed early the following day. The price—$7.2 million—amounted to about two cents per acre. Reportedly, the popular dessert baked Alaska was created to celebrate the acquisition of the territory.

Some newspapers—particularly Horace Greeley’s New York Tribune—savaged the decision, variously deeming the new territory “Seward’s Icebox,” “Seward’s Folly,” and “Walrussia.” However, most Americans were ambivalent; some supported the decision as a step toward the annexation of Canada. The treaty was submitted to the Senate for consent on March 30, 1867. Early opponent Sen. Charles Sumner—swayed in part by information about the territory’s abundant natural resources, gathered during Smithsonian Institution-sponsored expeditions in 1859 and 1865—spoke in its favour for more than three hours. It was passed on April 9. The United States officially took possession on October 18 in a flag-changing ceremony at Sitka. However, there was resistance to payment among members of the House, who were disinclined to support President Johnson, with whom they were unhappy over his dismissal of the Senate-appointed secretary of war (in defiance of the Tenure of Office Act). The House entered articles of impeachment in February 1868, but the attempt to oust him was unsuccessful. The necessary appropriations were ultimately passed on July 14, 1868. Extensive propaganda campaigns and judicious use of bribes by Stoeckl secured the required votes in each house of Congress.

Alaska remained under U.S. Army control until June 1877, after which it was governed briefly by the Treasury Department and then by various military authorities. Most Russians who had occupied the territory were not permanent residents and had returned to Russia following the sale. Those who remained were given the option of applying for U.S. citizenship within three years, but most eventually left. A civil government was installed in May 1884 after the territory became a district. Alaska was accepted into the union as the 49th state on January 3, 1959.