The name "Orcas" is a shortened form of "Horcasitas," from Juan Vicente de Güemes Padilla Horcasitas y Aguayo, 2nd Count of Revillagigedo, the Viceroy of Mexico who sent an exploration expedition under Francisco de Eliza to the Pacific Northwest in 1791. During the voyage, Eliza explored part of the San Juan Islands. He did not apply the name Orcas specifically to Orcas Island, but rather to part of the archipelago. In 1847, Henry Kellett assigned the name to Orcas Island during his reorganization of the British Admiralty charts. Kellett's work eliminated the patriotically American names that Charles Wilkes had given to many features of the San Juans during the Wilkes Expedition of 1838–42. Wilkes had named Orcas Island "Hull Island" after Commodore Isaac Hull. Other features of Orcas Island Wilkes named include "Ironsides Inlet" for East Sound and "Guerrier Bay" for West Sound. One of the names Wilkes gave remains: Mount Constitution. Wilkes's names follow a pattern: Hull was the commander of "Old Ironsides" (the ) and won fame after capturing the British warship HMS "Guerriere" in the War of 1812. The islands were first claimed by Spain, then by Britain, who agreed that everything below the 49th parallel was part of the US, in the treaty signed after the War of 1812. The Oregon territory, which then included Washington state and this island, was used jointly by the US and Britain until 1848, but border disputes specifically concerning the San Juan Islands, including the Pig War (1859), were not settled until 1871. The similarity to the name of the orca, which is popularly associated with coastal Washington state, is coincidental.