ROCK ISLAND, a city of western Illinois, U.S.A., on the Mississippi river, 180 m. W. by S. of Chicago, adjoining Moline and opposite Davenport, Ia. ; the county seat of Rock Island county. It is 2 M. above the mouth of the Rock river and the Hennepin canal (connecting the Mississippi and the Rock rivers with the Illinois), is on Federal highways 32 and 61, has air-mail service east, west and south, and is served by the Burlington Route, the Chicago, Milwaukee, St. Paul and Pacific, the Daven port, Rock Island and Northwestern, the Rock Island and the Rock Island Southern railways, and by river steamers and barges, ferries and motor-bus and truck lines. Pop. (1920) 35,177 (83% native white) ; 1930, 37,953 Federal census. The island from which the city takes its name, one of the largest (990 ac.) and most beautiful in the Mississippi, is owned by the U.S. Government, and occupied by an arsenal. Government bridges connect it with all three cities. Rock Island (the city) has an area of Io sq.m.
and an assessed valuation in 1926 of $12,056,116. It is the seat of Augustana college and Theological seminary (Evangelical Lutheran; 1860) and of the home offices of the Modern Woodmen of America and the Royal Neighbors of America (large fraternal orders). The manufacturing industries are important and diversi
fied, employing 3,8o6 workers and producing goods valued at $22,780,589 in 1927. On the tree-covered site of Rock Island there were villages (dating from as early as 1730) of the Sauk and Fox Indians, who helped the British in the War of 1812. The island was fortified by the British, and engagements took place in the vicinity in July and Oct. 1814. In 1816 the United States built Ft. Armstrong (abandoned 1836) on the west end of the island. It became one of the important frontier military posts, and was the headquarters of operations in the Black Hawk War and the scene of the signing of the treaty on Sept. 21, 1832. Black Hawk was born in one of the villages on the Rock river, and a bluff near its mouth is called Black Hawk's Watch-tower. The first white settlement on the mainland was made in 1826. The town was incorporated in 1837 and was chartered as a city in 1849. The arsenal was established on Rock Island by act of Congress in 1862. During the Civil War 12,000 Confederate soldiers were confined on the island, of whom 2,000 died during imprisonment.