President Donald Trump has said he believes the US will gain control of Greenland, after showing renewed interest in acquiring the autonomous Danish territory in recent weeks. "I think we're going to have it," he told reporters on Air Force One on Saturday, adding that the island's 56,000 residents "want to be with us".

Yet, just as his counterparts did in the past, Trump may find that "buying the Arctic" is not as straightforward as he thinks. In 1865, in the wake of the Civil War, the U.S. began looking to expand its influence on the world stage.