The land called Illinois Country (which included the current states of Iowa, Illinois, Missouri, Michigan, Wisconsin, part of Indiana and part of Arkansas) went through different government ownerships.
In 1673, the 1st white explorers were Jaques Marquette and Father Louis Joliet of France. They sailed from the Fox River to the Mississippi River and then back up the Illinois River to Fort Dearborn at Chicago. Once there, they claimed the land for France while additional French explorers followed and claimed more land for their native country.
Battle for the Illinois Country
In 1765, Thomas Sterling of England battled the French and won, taking over Illinois Country. After the Declaration of Independence in 1776, Colonel George Rogers Clark began fighting for Patrick Henry, who was the current Governor of Virginia. They fought the English and won the Illinois Country. This extended Virginia from the Atlantic ocean to the Mississippi River in a strip about the width of the Illinois.
Because some of the smaller states would not join the United States with Virginia being so big, Virginia gave control of Illinois Country to the United States in 1784. President Thomas Jefferson divided the land into territories. Illinois Territory was formed in 1801.
Illinois Introduced as a State
Nathaniel Pope, Illinois Senator, at the insistence of the settlers, worked to make Illinois a state. Pope insisting that Illinois have 50 miles of Wisconsin's southern border so Illinois could have a shipping port on Lake Michigan. If this had not been done, Batavia and Chicago would now be in Wisconsin. Congress approved, making Illinois the 21st state on December 3, 1818.