Last August President Trump announced that he was considering making an offer to buy Greenland. But is the idea of America buying an entire other country such a ridiculous concept? In fact, in 1916 when America bought the Caribbean islands that we now know as the US Virgin Islands from Denmark the US actually agreed as part of the deal that Greenland would fall within the Kingdom of Denmark. And that's not the only example: looking back through history many countries have purchased sovereign territory. Click or scroll through for 31 other examples of nations buying all, or parts of, other nations.