1940 Oil field near Salem, IllinoisThere are two main centers of commerce for southern Illinois. They consist of the of St. Louis, Missouri Metropolitan area (home to approximately 2.8 million people), and the Carbondale, Marion, Herrin, Harrisburg area (home to approximately 245,000 people).
 The main agricultural products of southern Illinois are crops such as corn, soybeans and apples. In recent years there has been a flourishing of wineries in the Shawnee region.
 Southern Illinois also has significant coal deposits, however since the late 1980's the coal industry has suffered significant decline due to the decreased demand for high sulfur coal. The collapse of the coal industry has had profound and lasting impact on the region's economy.
 The Illinois oil basin is located mostly in Little Egypt. During the early 1940s and 1950s, Little Egypt had a modest oil boom in towns such as Carmi, McLeansboro, and Lawrenceville. Oil production reached more than 140 million barrels per year in the 1940s, but dropped to 10 million barrels per year in 1995. Oil wells are still found in the region, but are of relatively low yield and produce oil with a high sulfur content. There has been no significant drilling activity in the basin since the late 1970s.
 Manufacturing in southern Illinois is typically clustered in the largest towns of each county, with the people of smaller towns and villages often commuting to them to work in the factories. Many of these towns have a number of light factories and other industrial facilities in their industrial parks which produce industrial electronics, minor electrical items, automobile parts, packaging materials, and carry out large scale printing as well as transportation and distribution of warehoused materials and goods. A large percentage of local jobs are in these light industries.