Plan a Trip by Era

Humans have inhabited what is today Illinois for over 12,000 years.  By about 700 A.D. native peoples had begun to establish permanent settlements that included large human-made earthen mounds used for burial ceremonies and other tribal rituals throughout Illinois.  Portions of these mounds survive today.

Jacques Marquette and Louis Jolliet crossed portions of what is now Illinois in 1673, extending the reach of New France in America.  France dominated the Mississippi Valley for almost a century, surrendering most of its North American claims to Great Britain in 1763.  For much of the period settlements anchored on the Mississippi between Cahokia and Kaskaskia served as a breadbasket of French Louisiana.

The capture of Kaskaskia by a small American revolutionary army in July 1778 established a claim by the new United States to the Illinois Country. The 1783 Treaty of Paris formally awarded the area west of the Mississippi River to the new nation.  Many French settlers crossed the Mississippi, uneasy with the thought of living under American government.  Others stayed on, operating businesses and participating in establishing the new government.

On December 3, 1818, Illinois became the twenty-first state of the Union.  Over the next thirty years the state experienced a transition from largely empty frontier to a settled and rapidly developing agricultural state.  Technology helped to change agriculture and develop extended markets.  It also fostered change in government, legal, and educational institutions.

The period that opened with adoption of a new state constitution saw continued growth in agricultural and industrial production.  The state’s population grew rapidly with settlers from other states, but especially due to immigration from German states and Ireland.  Growing debate over the role of slavery in the life of the nation raised tensions to a level that finally sundered the Union.  As the home of Stephen A. Douglas—a national leader of the Democrats—and of a skilled Republican challenger in the form of Abraham Lincoln, Illinois was a crucial battleground during the decade that ended in war.  The state contributed mightily to the Union cause, providing its commander-in-chief, numerous military leaders, more than 220,000 soldiers and sailors, and large volumes of agricultural and manufactured products.

Following the Civil War Illinois continued to grow in population, diversity, and complexity.  Large-scale heavy manufacturing and a growing commercial sector joined agriculture as major employers of a rapidly growing population.  Immigration continued, with African Americans from the South and southern and eastern Europeans joining more established groups.  Conflicting interests sometimes led to unrest, strikes, and even violence.  During this period Illinois also became a center of exciting new movements in art, architecture, and literature.

The state’s Modern Era has been one of continued growth and change.  Following the nation’s greatest economic collapse public works projects of the New Deal brought history to life, working to protect a number of historic places around the state.  Beginning in 1941, the state’s agricultural and manufacturing sectors and the sacrifices of citizen-soldiers played an important role in making possible the United States’ move to center of the world stage.