The Rock Island Arsenal comprises , located on Arsenal Island, originally known as Rock Island, on the Mississippi River between the cities of Davenport, Iowa, and Rock Island, Illinois. It lies within the state of Illinois. Rock Island was previously used as the summer camp site for Sauk Native Americans, and the dispute over tribal ownership led to the Black Hawk War of 1832, after the primary leader of the Sauk, Black Hawk. It is now home of First Army headquarters, and the US Army's Center of Excellence for Additive Manufacturing. The island was originally established as a government site in 1816, with the building of Fort Armstrong. It is now the largest government-owned weapons manufacturing arsenal in the United States. It has manufactured military equipment and ordnance since the 1880s. In 1919–1920 one hundred of the Anglo-American or Liberty Mark VIII tanks were manufactured, although too late for World War I. It is designated as a National Historic Landmark. Established as both an arsenal and a center for the manufacture of leather accoutrements and field gear, today it provides manufacturing, logistics, and base support services for the Armed Forces. The Arsenal is the only active U.S. Army foundry, and manufactures ordnance and equipment, including artillery, gun mounts, recoil mechanisms, small arms, aircraft weapons sub-systems, grenade launchers, weapons simulators, and a host of associated components. Some of the Arsenal's most successful products include the M198 and M119 towed howitzers, and the M1A1 gun mount. About 250 military personnel and 6,000 civilians work there. The 2000 census population was 145. History From the autobiography of Sauk Native American Black Hawk: "When we arrived we found that the troops had come to build a fort on Rock Island...We did not object, however, to their building their fort on the island, but were very sorry, as this was the best one on the Mississippi, and had long been the resort of our young people during the summer. It was our garden, like the white people have near their big villages, which supplied us with strawberries, blackberries, gooseberries, plums, apples and nuts of different kinds." The island facilities were converted and built in 1863; they were not yet completed in December of that year, when the first Confederate prisoners were incarcerated. The construction was makeshift. The first prisoners were 468 Confederates captured in battles at Chattanooga, Tennessee. That month more than 5,000 Confederates would