evidence: Navassa Island is an uninhabited island, less than two square miles in size, in the Caribbean Sea, between Jamaica and Haiti. Like many of these Minor Outlying Islands, it became a possession of the US as part of the Guano Islands Act, passed by US Congress in 1856, which allowed US citizens to claim any island with potential mineable deposits of bird guano, not already claimed by another nation, as "appertaining" to the United States (after Presidential approval). Within eight years, 59 islands in the Atlantic and the Pacific were claimed in this way, and over time these were mined for their nitrate-rich guano, for use as fertilizer – if they had any. [...] Mining ended in 1898, and the island was abandoned, until a lighthouse with a keeper’s residence was built in 1917. In 1929 the lighthouse was automated, and the island unoccupied again. Navassa saw some activity as an observation post in World War Two, but then was abandoned again. In 1999 the Navassa Island National Wildlife Refuge was established, which covers the island and the surrounding 12-mile ring of territorial waters. US Fish and Wildlife Service manages the refuge as one of 14 official territories of the USA; although since 1857 Navassa has also been claimed by Haiti, which is just 35 miles away. It is off limits to the public.