USA Illinois | North America

Geography and Environment

Illinois is situated in the Midwestern United States, covering about 57,914 square miles (149,997 km²). The state is geographically diverse, featuring three major regions:

Northern Illinois: Characterized by the Chicago metropolitan area and its surrounding suburbs, it has a relatively flat terrain but includes some gently rolling hills and river valleys.

Central Illinois: Known as the “Prairie State,” this region consists mainly of flat to gently rolling farmland and is part of the larger Central Plains.

Southern Illinois: More hilly and forested compared to the north and central regions, with some parts influenced by the Shawnee National Forest, although not focusing on landmarks here.

The state is drained by several major rivers, including the Illinois River, Mississippi River (forming the western boundary), and Ohio River (to the southeast). Illinois’ terrain gradually slopes from the higher elevations in the north and northwest down towards the Mississippi River valley.

Climate

Illinois experiences a humid continental climate:

Winters are cold, with temperatures often below freezing and occasional snowfall.

Summers are warm to hot and humid, with temperatures frequently reaching into the 80s and 90s Fahrenheit (27–35°C).

Spring and fall are transitional seasons with variable weather, including thunderstorms in the spring.

Due to its position in the Midwest, Illinois is also susceptible to severe weather such as tornadoes and strong thunderstorms.

Demographics

Illinois has a population of approximately 12.5 million people, making it the sixth most populous state in the U.S. Its population distribution includes:

Urban areas: The northeastern region, centered around Chicago, contains the bulk of the state’s population and economic activity.

Suburban communities: Surrounding Chicago and other cities, these areas are home to many residents who commute for work or business.

Rural regions: Central and southern Illinois have smaller towns and farming communities with lower population density.

Ethnically and culturally, Illinois is diverse. The Chicago metropolitan area in particular hosts a wide variety of ethnic groups and immigrant communities. The state’s demographics include a significant African American population, Hispanic communities, and other minority groups.

Economy

Illinois has one of the largest and most diversified economies in the United States, driven by several key sectors:

Agriculture: Illinois is a leading producer of corn and soybeans, benefiting from its fertile prairie soils. It also produces significant amounts of livestock and dairy products.

Manufacturing: The state has a strong industrial base producing machinery, chemicals, food products, transportation equipment, and more.

Finance and services: Particularly in Chicago, finance, insurance, real estate, and professional services are major economic drivers.

Transportation and logistics: Illinois’ central location makes it a major hub for freight and passenger transportation, supported by a comprehensive network of highways, railroads, airports, and inland waterways.

Energy: Illinois produces coal, nuclear power, and renewable energy resources, contributing to its energy mix.

Government and Politics

Illinois operates under a state government system with three branches:

Executive: Led by the Governor, responsible for state administration.

Legislative: Bicameral General Assembly consisting of the Senate and House of Representatives, making state laws.

Judicial: Includes the Illinois Supreme Court and lower courts.

The state’s political landscape is often characterized by a balance between heavily Democratic urban areas, especially Chicago, and more conservative rural regions. This mix influences elections and policy decisions at both state and national levels.

Education and Health

Illinois has a broad system of education:

Public school districts across urban, suburban, and rural areas serve millions of students.

Numerous higher education institutions, including public universities, community colleges, and private colleges, contribute to workforce development and research.

The healthcare system includes a network of hospitals, clinics, and specialized medical centers providing services to urban and rural populations alike. Public health programs focus on disease prevention, mental health, and access to care.

Infrastructure

Illinois boasts well-developed infrastructure to support its economy and residents:

A dense network of interstate highways and state roads connects communities.

Extensive rail systems handle both freight and passenger services.

Several major airports serve domestic and international travel needs.

River ports and waterways facilitate the transport of agricultural and industrial goods.

Natural Resources and Environment

Illinois’ natural resources include fertile soil for agriculture, coal deposits, and water resources from its rivers and lakes. Environmental concerns in the state focus on maintaining air and water quality, managing industrial pollution, and preserving green spaces amid urban growth.

This detailed profile outlines Illinois’ physical characteristics, population, economy, governance, and infrastructure, presenting a comprehensive view without highlighting specific landmarks.