evidence: The island of Navassa is about 30 miles off the coast of Haiti and is covered in centuries’ worth of accumulated bird droppings—guano. Sometimes referred to as "white gold," guano is a potent fertilizer that in the mid-1800s was a scarce resource for which American farmers were desperate. Peru had large amounts of the stuff, but its near monopoly position and special deal with Britain meant that American farmers were priced out. In 1850, guano was $76 a pound—a quarter of the price of gold at the time. The situation was so dire that President Millard Fillmore devoted portions of his 1850 State of the Union address to the subject. [...] Haiti, for its part, has continued to quietly maintain its claim to Navassa—the constitution of Haiti even says so. But Haiti’s near-vassal state relationship with the U.S. over the past century-and-a-half has meant that no Haitian government has been willing to bring formal claims for the unlawful taking of its property. [...] But maybe we can start small, with the taking of that little island covered in bird droppings. Navassa is a tangible, transferable piece of real property that was taken from Haiti at a time when it was covered in one of the world’s most valuable assets. Whether we call it a debt, damages, reparations, or an offer to settle a disputed claim, it is long past time for the U.S. to pay up.