On October 18, 1867, the U.S. formally took possession of Alaska
after purchasing the territory from Russia for $7.2 million, or less
than two cents an acre.

Indigenous peoples had settled the unforgiving territory thousands
of years earlier. The Alaska purchase comprised 586,412 square
miles, about twice the size of Texas, and was championed by
William Henry Seward, the enthusiastically expansionist
secretary of state under President Andrew Johnson.

Signing of the Alaska Treaty, The Alaska Purchase.