The Alto Velo Claim, also referred to as the Alta Vela Affair, was a territorial claim against the Dominican government by American adventurers ejected from Alto Velo Island by Dominican officials in October 1860. In all, three companies claimed U.S. protection of their right to mine guano from the island under the Guano Islands Act of 1856, but the U.S. Department of State never recognized U.S. control over the island. Claim dispute The initial claim on the island, located some south of Hispaniola, was established on March 19, 1860, by Captain R. Daubley of the brig Delta, who landed on the island, loaded the ship with guano, and departed after noting some of guano deposits. A chemical analysis of the guano retrieved found it to consist of 29.16 percent phosphoric acid and 70.84 percent bone phosphate of lime. Under the Guano Islands Act of 1856, W.T. Kendall filed a claim on the island with the U.S. Department of State in mid-May 1860. Around the same time, a second claim on the island was filed by the Baltimore-based firm Patterson & Murguiondo, based on a visit to the island by Captain S.R. Kimball of the schooner Boston on February 23, 1860. The State Department advised that the island, based on its name, may have been previously discovered by Spain, and thus under the control of the Dominican Republic. Representatives of Patterson & Murguiondo claimed to work the guano deposits from March 1860 to October 24, 1860, at which time the Dominican warship Mercedes arrived at the island under the command of Francisco Nio. The Dominicans landed with an artillery corps led by General Juan Evertsz to assert Dominican control over the island, ordering the foreigners to depart within 24 hours. Without a ship to remove them, 12 workers were taken prisoner and brought to the capital, Santo Domingo. The Dominicans also demolished the company's buildings on the island proper. An American investigation of the incident determined that Alto Velo fell into an area then-disputed between Haiti and the Dominican Republic, and which neither country had established a clear claim or record of occupation. Due to the U.S. Civil War and the unsuccessful Spanish reoccupation of the Dominican Republic occurring simultaneously, work on the Alto Velo Claims was suspended from 1861 to 1865, resuming after the U.S. and the Dominican Republic established formal political relations in 1865. In February 1866, a third