Final answer:
The nickname given to Alaska after its purchase in 1867 was 'Seward's Folly', reflecting the initial skepticism towards the decision. The purchase, however, turned out to be beneficial for the United States.
Step-by-step explanation:
The nickname given to Alaska after it was purchased in 1867 was Seward's Folly. This nickname originated from critics who believed that Secretary of State William Seward had made a foolish decision to spend $7.2 million on Alaska, thinking it was a wasteland. However, the purchase turned out to be a strategic move as it brought vast natural resources and later became a valuable part of the United States.
Learn more about Alaska's Purchase