St. Clair County, Illinois

St. Clair County, Illinois Soundex Code S324

Wikipedia page about St. Clair County, Illinois

St. Clair County, Illinois was the first county established in what is today Illinois. In fact the county antedates Illinois' existence as a separate entity. It was established in 1790 by proclamation of Arthur St. Clair, first governor of the Northwest Territory, who named it after himself.

In its original boundaries, St. Clair County, Illinois covered a large area between the Mackinaw River and Ohio River. In 1801, Governor William Henry Harrison re-established St. Clair County, Illinois as part of the Indiana Territory, extending its northern border to Lake Superior and the international border with Rupert's Land.

In 1809, when the Illinois Territory was created, Territorial Secretary Nathaniel Pope, in his capacity as acting governor, issued a proclamation establishing St. Clair County, Illinois and Randolph County, Illinois as the two original counties of Illinois.