evidence: "The United States has no valid claim over Navassa Island," said Fritz Longchamp, a former Haiti foreign minister who in 1998 had to deal with the U.S.’s revived claims to the deserted outpost while serving in then-Haitian president Rene Preval first cabinet. [...] The United States’ claim on Navassa dates back to Peter Duncan. After coming across the guano-covered island, he took possession of it on Sept. 19, 1857, according to an 1891 Supreme Court case his widow later filed against the Navassa Phosphate Company. [...] Returned back to the United States, three of the workers were eventually convicted of murder and sentenced to death, and others were found guilty of manslaughter. When their lawyers appealed the case on the grounds that Navassa wasn’t a U.S. territory, the U.S. Supreme Court declared that it was as part of a review of the constitutionality of the Guano Islands Act.