Why did many people mock William Seward's purchase of Alaska?

Russia initially approached the United States about selling the territory during President James Buchanan‘s administration, but the Civil War stalled negotiations. Seward, secretary of state under presidents Abraham Lincoln and Andrew Johnson, supported American expansion and was eager to acquire Alaska. However, convincing skeptics that Alaska was an important addition to the United States was a challenge. Thanks to strong support by Senator Charles Sumner of Massachusetts, then chairman of the Foreign Relations Committee, the Senate approved the treaty by a vote of 37-2 on April 9, 1867. Nonetheless, the appropriation of money needed to purchase Alaska was delayed by more than a year due to opposition in the House of Representatives. The House finally approved the appropriation on July 14, 1868, by a vote of 113-43.