Illinois campaign in the context of "Patriot (American Revolution)"

Illinois (/ˌɪlɪˈnɔɪ/ IL-ih-NOY) is a state in the Midwestern region of the United States. It borders Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash and Ohio rivers to its south. Of the fifty U.S. states, Illinois has the fifth-largest gross domestic product (GDP), the sixth-largest population, and the 25th-most land area. Its capital city is Springfield in the center of the state, and the state's largest city is Chicago in the northeast.

Present-day Illinois was inhabited by Indigenous cultures for thousands of years. The French were the first Europeans to arrive, settling near the Mississippi and Illinois rivers in the 17th century Illinois Country, as part of their sprawling colony of New France. A century later, the revolutionary war Illinois campaign prefigured American involvement in the region. Following U.S. independence in 1783, which made the Mississippi River the national boundary, American settlers began arriving from Kentucky via the Ohio River. Illinois was soon part of the United States' oldest territory, the Northwest Territory, and in 1818 it achieved statehood. The Erie Canal brought increased commercial activity in the Great Lakes, and the invention of the self-scouring steel plow by Illinoisan John Deere turned the state's rich prairie into some of the world's most productive and valuable farmland, attracting immigrant farmers from Germany, Sweden and elsewhere. In the mid-19th century, the Illinois and Michigan Canal and a sprawling railroad network facilitated trade, commerce, and settlement, making the state a transportation hub for the nation, especially in the city of Chicago, which became the world's fastest growing city by the late 19th century. By 1900, the growth of industrial jobs in the northern cities and coal mining in the central and southern areas attracted immigrants from Eastern and Southern Europe. Illinois became one of America's most industrialized states and remains a major manufacturing center. The Great Migration from the South established a large Black community, particularly in Chicago, which became a leading cultural, economic, and population center; its metropolitan area, informally referred to as Chicagoland, holds about 65% of the state's 12.8 million residents.

George Rogers Clark (November 19, 1752 – February 13, 1818) was an American military officer and surveyor from Virginia who became the highest-ranking Patriot military officer on the northwestern frontier during the Revolutionary War. He served as leader of the Virginia militia in Kentucky (then part of Virginia) throughout much of the war. He is best known for his captures of Kaskaskia in 1778 and Vincennes in 1779 during the Illinois campaign, which greatly weakened British influence in the Northwest Territory (then part of the British Province of Quebec) and earned Clark the nickname of "Conqueror of the Old Northwest". The British ceded the entire Northwest Territory to the United States in the 1783 Treaty of Paris.

Clark's major military achievements occurred before his thirtieth birthday. Afterward, he led militia forces in the opening engagements of the Northwest Indian War, but was accused of being drunk on duty. He was disgraced and forced to resign, despite his demand for a formal investigation into the accusations. Clark left Kentucky to live in the Indiana Territory but was never fully reimbursed by the Virginian government for his wartime expenditures. During the final decades of his life, he worked to evade creditors and suffered living in increasing poverty and obscurity. He was involved in two failed attempts to open the Spanish-controlled Mississippi River to American traffic. Following a stroke and the amputation of his right leg, he became disabled. Clark was aided in his final years by family members, including his younger brother William, one of the leaders of the Lewis and Clark Expedition. He died of a stroke on February 13, 1818.