Nauvoo [nah VOO, naw VOO]. Hancock. City (1841, 1899) six miles south of Fort Madison, Iowa. The area around modern Nauvoo was known as Quashquema, named for a minor Sauk leader of the late eighteenth and early nineteenth centuries. Quashquema (Jumping Fish) was coerced or tricked by William Henry Harrison into signing over a large tract of northwestern Illinois to the United States in 1804. The community was established as Venus in the 1820s by early settler James White and was later known as Commerce. When the Mormons were expelled from Missouri in 1839, they crossed the Mississippi River and established Nauvoo on the site. Joseph Smith, the founder and prophet of the Mormon Church, created the name, claiming that he had derived it from the Hebrew root nawa (na-va) and that it meant “beautiful lace” (Bateman and Selby, eds., Historical Encyclopedia of Illinois and History of Hancock County, 834, 1089; Hagan, The Sac and Fox Indians, 25; History of Hancock County, 394). Post office established March 13, 1830, as Venus; changed to Commerce Oct. 11, 1834; changed to Nauvoo April 21, 1840.
From Place Names of Illinois by Edward Callary