Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Rock Island Arsenal comprises 946 acres (3.83 km2; 1.478 sq mi), 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. 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.