Illinois Homeland Security and Emergency Services Resources

Several mounds can be found throughout Illinois marking the presence of the Indians that lived and hunted in the state as early as 5,000 B.C. But, the first European explorers didn't discover the land until 1673 when Frenchmen Jacques Marquette and Louis Joliet traveled the length of the state.

By 1699, French traders had established a trading post and a permanent settlement near what is now East St. Louis. More French settlers followed and along with building several military outposts, they also started an empire by fur trading with the local Indians.

There had been six different forms of government operating in the state at various times before the first Illinois constitution came into effect in 1818. That same year, Illinois became the 21st state to enter the Union. In 1825, the construction of the Erie Canal drew hundreds of new settlers from the eastern states and from Europe.

After the Civil War ended in 1865, the states industry boomed. Immigrants came to work in the factories, railroads expanded and Chicago led the country in meatpacking and grain. But, tragedy struck in 1871 when the Great Chicago Fire destroyed the city killing over 300 people and blazing for almost two days.

During World War II, Illinois produced both ammunition and aircraft. Several research centers in the state have helped to develop nuclear technology. The University of Chicago is responsible for a major development in the atomic bomb, creating the first controlled nuclear chain reaction.