Alaska was originally part of the Russian Empire. In 1867, the Russian Empire sold the territory to the United States. This is known as the Alaska Purchase. This short article about history can be made longer. You can help Wikipedia by adding to it. This short article about the United States can be made longer. You can help Wikipedia by adding to it. The cheque that was used to pay for the Alaska territory: $7.2 million U.S. dollars at the time are about $121 million U.S. dollars in 2015.