Illinois was the 21st state in the USA; it became a state on December 3, 1818.
State Abbreviation - IL
State Capital - Springfield
Largest City - Chicago
Area - 57,918 square miles [Illinois is the 25th biggest state in the USA]
Population - 12,419,293 (as of 2000) [Illinois is the fifth most populous state in the USA, after California, New York, Texas, and Florida]
Name for Residents - Illinoisan
Major Industries - agriculture (corn, soybeans, wheat, oats, barley, rye, sorghum), cattle, manufacturing, mining

Presidential Birthplace - Ronald Wilson Reagan was born in Tampico on February 6, 1911 (he was the 40th US President, serving from 1981 to 1989)

Major Rivers - Mississippi River, Ohio River, Illinois River, Wabash River
Major Lakes - Lake Michigan, Rend Lake
Highest Point - Charles Mound - 1,235 feet (376 m) above sea level
Bordering States - Indiana, Kentucky, Missouri, Iowa, Wisconsin
Bordering Body of Water - Lake Michigan

Origin of the Name Illinois - Illinois comes from the word Illini, a confederation of the Cahokia, Kaskaskia, Michigamea, Moingwena, Peoria and Tamaroa Indian tribes.
State Nickname - Prairie State
State Motto - State Sovereignty, National Union
State Song - "Illinois"

Illinois State Symbols and Emblems:
State Flag
Illinois's original state flag was designed in 1913 by Lucy Derwent (who had won a contest), but was redesigned in 1970 by Mrs. Sanford Hutchinson. The flag's design is based upon the state's seal, which was designed by Sharon Tyndale, Illinois' secretary of state, in 1868.

The flag has a white background, and much of the Illinois state seal is pictured in the center. There is a bald eagle perched on a rock holding a red, white, and blue shield in its talons (the stars are white on a blue background and the stripes are red and white). The shield has 13 stripes and 13 stars, representing the original 13 colonies of the USA. The eagle is holding a banner in its beak which reads "STATE," "SOVEREIGNTY," "NATIONAL," and "UNION." The word sovereignty is upside down. The rock has the dates 1818 and 1868 written on it; 1818 refers to the year Illinois became a state and 1868 refers to the date the state seal was redesigned.

Animal Symbols:
State Bird
Cardinal
State Mammal
White-tailed deer
State Insect
Monarch Butterfly

State Fish
Bluegill
Plant Symbols:
State Flower
Illinois Native (purple) Violet

State Tree
White oak
(Quercus alba )
State Grass
Big bluestem

Earth Symbols:
State Fossil
Tully Monster
(Tullimonstrum gregarium)
A soft-bodied sea animal that lived roughly 280 to 340 million years ago during the Carboniferous period.
State Mineral
Fluorite

1. Ottawa, Freeport, Jonesboro, Charleston, Galesburg, Quincy and Alton hosted the famous Lincoln-Douglas debates that stirred interest all over the country in the slavery issue.
   
2. The first Aquarium opened in Chicago, 1893.
   
3. The world's first Skyscraper was built in Chicago, 1885.
   
4. Home to the Chicago Bears Football Team, Chicago Blackhawks hockey team, Chicago Bulls basketball team, Chicago Cubs and Chicago Whitesox baseball teams, Chicago Fire soccer team.
   
5. The first Mormon Temple in Illinois was constructed in Nauvoo.
   
6. Peoria is the oldest community in Illinois.
   
7. The Sears Tower, Chicago is the tallest building on the North American continent.
   
8. Metropolis the home of Superman really exists in Southern Illinois.
   
9. Cahokia Mounds State Historic Site--most sophisticated prehistoric native civilization north of Mexico
   
10. Illinois had two capital cities, Kaskaskia, and Vandalia before Springfield.
    
11. The NFL's Chicago Bears were first known as the "Staley Bears". They were organized in 1920, in Decatur.
    
12. Illinois was the first state to ratify the 13th Amendment to the Constitution abolishing slavery. 1865
    
13. On December 2, 1942, Enrico Fermi and a small band of scientists and engineers demonstrated that a simple construction of graphite bricks and uranium lumps could produce controlled heat. The space chosen for the first nuclear fission reactor was a squash court under the football stadium at the University of Chicago.
    
14. Des Plaines is home to the first McDonald's.
    
15. Dixon is the boyhood home of President Ronald Reagan.
    
16. Springfield is the state capital and the home of the National Historic Site of the home of President and Mrs. Abraham Lincoln.
    
17. Chicago is home to the Chicago Water Tower and Pumping Station, the only buildings to survive the Great Chicago Fire.
    
18. Before Abraham Lincoln was elected president he served in the Illinois legislature and practiced law in Springfield. Abraham Lincoln is buried just outside Springfield at Lincoln Tomb State Historic Site.
    
19. Carlyle is the home of the largest man-made lake in Illinois.
    
20. Illinois has 102 counties.
    
21. Ronald Wilson Regan from Tampico became the 40th president of the United States in 1980.
    
22. The highest point in Illinois is Charles Mound at 1235 feet above sea level.
    
23. The state motto is: State Sovereignty, National Union
    
24. The ice cream "sundae" was named in Evanston. The piety of the town resented the dissipating influences of the soda fountain on Sunday and the good town fathers, yielding to this churchly influence, passed an ordinance prohibiting the retailing of ice cream sodas on Sunday. Ingenious confectioners and drug store operators obeying the law, served ice cream with the syrup of your choice without the soda. Objections then was made to christening a dish after the Sabbath. So the spelling of "sunday" was changed. It became an established dish and an established word and finally the "sundae".
    
25. The round Silo for farm storage of silage was first constructed on a farm in Spring Grove.
    
26. The Illinois state dance is square dancing.
    
27. Illinois has more units of government than any other state (i.e., city, county, township, etc.). Over six thousand. One contributing reason may be the township governments, which are generally six miles square.
    
28. The worst prison camp during the Civil War in terms of percentages of death was at Rock Island.
    
29. Illinois boasts the highest number of personalized license plates, more than any other state.
    
30. The University of Illinois Conservatory is 37 feet high at its apex.
    
31. In 1905, president of the Chicago Cubs filed charges against a fan in the bleachers for catching a fly ball and keeping it.
    
32. Chicago's Mercantile Exchange building was built entirely without an internal steel skeleton, as most skyscrapers; it depends on its thick walls to keep itself up
    
33. The abbreviation "ORD" for Chicago's O'Hare airport comes from the original name Orchard Field. O'Hare Airport was named in honor of Lieutenant Commander Edward H. "Butch" O'Hare.
    
34. The trains that pass through Chicago's underground freight tunnels daily would extend over ten miles total in length.
    
35. The slogan of 105.9, the classic rock radio station in Chicago: 'Of all the radio stations in Chicago...we're one of them.'
    
36. In Mount Pulaski, Illinois, it is illegal for boys (and only boys) to hurl snowballs at trees. Girls are allowed to do that however.
    
37. In Illinois Michael is the top name chosen for boys. Emily is the most chosen name for girls.
    
38. Illinois is known for its wide variety of weather. Major winter storms, deadly tornadoes and spectacular heat and cold waves.
    
39. The first birth on record in Chicago was of Eulalia Pointe du Sable, daughter of Jean-Baptiste Pointe du Sable and his Potawatomi Indian wife in 1796.
    
40. Chicago's Mercy Hospital was the first hospital opened in Illinois.
    
41. The first animal purchased for the Lincoln Park Zoo was a bear cub, bought for $10 on June 1st, 1874
    
42. The University of Chicago opened on October 1, 1892 with an enrollment of 594 and a faculty of 103.
    
43. New York Sun editor Charles Dana, tired of hearing Chicagoans boast of the world's Columbian Exposition, dubbed Chicago the "Windy City."
    
44. Comedy showcase "Second City" was founded on North Wells Street in a former Chinese laundry in 1959
    
45. Chicago's first African American mayor, Harold Washington, took office in 1983
    
46. The 4 stars on the Chicago flag represent Fort Dearborn, the Chicago Fire, the World's Columbian Exposition, and the Century of Progress Exposition.
    
47. The Chicago Public Library is the world's largest public library with a collection of more than 2 million books.
    
48. The Chicago Post Office at 433 West Van Buren is the only postal facility in the world you can drive a car through.
    
49. The Chicago River is dyed green on Saint Patrick's Day.
    
50. The world's largest cookie and cracker factory, where Nabisco made 16 billion Oreo cookies in 1995, is located in Chicago.
    

* data from http://www.enchantedlearning.com and http://www.50states.com