イリノイ郡
The Illinois Country was a vaguely defined region which included much of the present U.S. states of Indiana and Illinois. The area had been a part of the Louisiana district of New France until the end of the French and Indian War/Seven Years' War, when France ceded sovereignty of the region to the British in 1763 Treaty of Paris. In the Quebec Act of 1774, the British made the Illinois country a part of its newly expanded Province of Quebec.