2. Which sentence contains a supporting detail that answers the question when? In 1867, the United States bought Alaska from Russia for about $7 million. Many Americans thought it was a foolish purchase. They thought Alaska was a wasteland of ice and snow. However, Alaska is rich in oil, fish, and lumber. The purchase of Alaska was a true bargain. In 1867, the United States bought Alaska from Russia for about $7 million. Many Americans thought it was a foolish purchase. However, Alaska is rich in oil, fish, and lumber. The purchase of Alaska was a true bargain.