For questions about ancestors and records in the US state of Illinois, including questions pertaining to the period before the state's admission to the US (1818) when it was a French colony, later British, and then an American territory.

Illinois is a state of the United States of America, between the middle reaches of the Mississippi River and the southern end of Lake Michigan.

Although the current population concentration is in the north of the state (including its largest city, Chicago), Illinois grew by migration from the south. It joined the USA in 1818.