About one fifth of the state’s people live
in rural areas.
The main institutions of higher education
are the University of Chicago;
Northwestern University, in Evanston;
and the University of Illinois, with campuses
in Urbana-Champaign, Chicago,
and Springfield.
Economy
The economy of Illinois is diverse. The
state is strong in finance, services, trade,
manufacturing, government, transportation,
and agriculture.
Illinois is a leading manufacturer of
machinery. It also ranks among the top
states in the manufacture of food products,
fabricated metal products, and
chemicals. The state is also a leader in
printing, publishing, broadcasting, and
telecommunications.
Illinois has ranked among the chief
farming states since about 1850. The
most valuable crops are corn and soybeans.
More than one fifth of Illinois’s
farm production comes from the sale of
livestock, especially hogs and cattle, and
livestock products.
The city of Chicago accounts for a large
share of Illinois’s population and economy.
Cornfields and other farmland cover large areas of the state of Illinois. Corn and soybeans
are the state’s leading crops.
Facts About
ILLINOIS
Flag
Population
(2000 census),
12,419,293—
rank, 5th state;
(2008 estimate)
12,901,563—
rank, 5th state
Capital
Springfield
Area
57,914 sq mi
(149,998 sq
km)—rank, 25th
state
Statehood
December 3,
1818
Motto
State Sovereignty,
National Union
State bird
Cardinal
State flower
Violet
BRITANNICA STUDENT ENCYCLOPEDIA Illinois 117
History
Native American settlement in Illinois
dates from about 8000 BC. Beginning in
about AD 800 Indians known as the
Mississippian people lived in the region.
They left behind thousands of earth
mounds that they had built up from the
prairie. The largest of these is Monks
Mound, in Cahokia in southwestern
Illinois. A number of Native American
peoples lived in the area when Europeans
arrived.
The French explorers Louis Jolliet and
Jacques Marquette entered the region in
1673. Illinois was controlled by the
French until 1763, when it passed to the
British. In 1778 George Rogers Clark
claimed the region for the United States.
The first settlement on the site of Chicago
was made in 1779 by black pioneer
Jean-Baptist-Point du Sable.
Illinois was officially given over to the
United States in 1783, at the end of the
American Revolution. It became the
21st state on December 3, 1818. Some
250,000 Illinoisans fought for the
Union during the American CivilWar.
In 1871 fire swept through Chicago,
destroying a third of the city. However,
the fire proved only a temporary
setback in the city’s rapid growth.
Many people moved there to help
rebuild the city. The workers were not
always treated well. Soon they began to
ask for better working conditions. By
the end of the 1800s Illinois was a
main focus of the labor movement.
Chicago was the site of several violent
confrontations between workers and
police. The two most famous events
were the Haymarket Square Riot of
1886 and the Pullman Strike of 1894.
In spite of this, Chicago and the rest of
Illinois underwent tremendous
economic and cultural growth.
The two parts of the state did not always
grow equally, however. The interests of
the big city and the small towns were
not always the same. This is reflected in
the state’s politics. Since the CivilWar,
the Republican and Democratic parties
have competed for power in Illinois.
Chicago is strongly Democratic. Much
of the rest of the state is Republican.
Most of Chicago’s suburbs are Republican
as well.
#More to explore
American CivilWar • Chicago • Du
Sable, Jean-Baptist-Point • Illinois,
People • Jolliet, Louis • Labor • Lincoln,
Abraham • Marquette, Jacques
• Springfield
The Lincoln Home National Historic Site is
located in Springfield, Illinois. It features the
house that Abraham Lincoln lived in for 17
years before he became president of the
United States.
118 Illinois BRITANNICA STUDENT ENCYCLOPEDIA
Immigration
#see Migration, Human.
Immune System
Most living things try to protect themselves
from harm. Animals have a special
protection called the immune system.
The immune system protects the body
from substances called antigens. Some of
the most harmful antigens are germs like
viruses and bacteria, which cause illness.
Parts of the immune system block antigens
from entering the body. Other
parts destroy the antigens that do enter.
The protection given by the immune
system is called immunity. Humans and
some animals have two basic types of
immunity: natural and acquired.
Natural Immunity
All animals, including humans, have
natural immunity. It works against any
antigen that enters or tries to enter the
body. Skin is a part of natural immunity.
It blocks many things from entering the
body. Mucus in the nose also blocks
antigens. In addition, most animals produce
special chemicals and cells that
attack antigens inside the body.
Acquired Immunity
Only human beings and other animals
with backbones have acquired immunity.
With this kind of immunity, certain
cells in the body can “remember”
the types of antigens they have attacked
in the past. This “memory” allows the
acquired immune system to attack these
