When Trump’s interest in buying Greenland was first reported that year, it struck critics as a characteristically provocative but unserious gambit—expansionist bluster from a President given to floating outlandish ideas. But Trump was serious. Nor was he the first Commander in Chief to entertain the idea. In the 19th century, William Seward, the Secretary of State who negotiated the purchase of Alaska under Andrew Johnson, argued the case for acquiring Greenland was “political and commercial,” citing its vast territory and mineral wealth. But no offer was ever made. President Harry Truman revived the idea in 1949, at one point proposing to purchase the island from Denmark in exchange for $100 million in gold and oil rights in Alaska.