Named for Hugh Mercer, a General of the Revolution, killed at the battle of Princeton.
County Population: 16,957
County Houses: 7,109
Land area: 561.0 sq. mi.
Water area: 7.9 sq. mi.
Rock Island County FYI
Named from rock island of that name in the Mississippi.
Rock Island County prior to its organization was included in the jurisdiction of Jo Davies County. In 1833 the Legislature passed an act declaring that all the territory embraced within the current county boundaries be known by the name of Rock Island. In pursuance of the provisions of this act, due notice was given to the legal voters to meet at the house of John Barrell (the first courthouse), in Farnhamsburg, on Monday, the 5th day of July, 1833, to elect three County Commissioners, one Sheriff, one Coroner, three Justices of the Peace and three Constables. The following were voted into office that day.
Rock Island County
Rock Island, County Seat
Courthouse contact information:
Rock Island County Courthouse
1504 Third Avenue
Rock Island, IL 61201
Named for Samuel Whiteside, a Colonel of the Territorial militia, Representative in the First General Assembly, and Brigadier General of the militia during the Black Hawk War.
On January 16, 1836, Whiteside County was formed with its current boundaries, but it continued to be attached to Jo Daviess County until December 1836 when it was attached to Ogle County. On May 6, 1839, the first Officers of Whiteside County were elected, and the county completed its organization thus terminating the connection with Ogle County.
