Jackson County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 60,218. Its county seat is Murphysboro, and its most populous city is Carbondale, home to the main campus of Southern Illinois University. The county was incorporated on January 10, 1816 and named for Andrew Jackson.
Human occupation of Jackson County began about 11,500 years ago. Extensive documentation of the areas indigenous peoples has been conducted and is ongoing. Exploration from the European explorers began with the Joliet-Marquette exploration along the Mississippi River. It was not until the 18th and 19th century when pioneer farmers began to settle in the area's inexpensive land along the Mississippi River and in the forested Shawnee hills with its one-hundred-foot trees.
As early as 1813, Conrad Will, namesake of Will County, conducted a large salt extraction operation using slave labor on the banks of the Big Muddy River, south of today's Murphysboro. As this was in the "free" Northwest Territory, Will had to have a legal exemption to own slaves.
Shortly after the American Civil War, General John A. Logan led a parade of veterans from Murphysboro to Carbondale, Illinois. General Logan, himself a Union veteran, invited the Confederate veterans, of which there were many in somewhat divided Jackson County, to march with him. What might have been another celebration of the Union victory became a memorial to the war dead on both sides. This is one possibility of the origin of the Memorial Day holiday.
In 1925 the great Tri-State Tornado ripped through Jackson County on March 18, leaving devastation in its path. The villages of Gorham and DeSoto and the city of Murphysboro were especially hit hard.
The county courthouse is in downtown Murphysboro. The current reinforced concrete courthouse replaced earlier wooden structures and was built during 1927-28. The original county seat and courthouse were located along the Big Muddy River at . After the court house in Brownsvillewas destroyed by fire, the county government was moved upstream a few miles to Murphysboro. Few traces now remain of the old town of Brownsville. On February 27, 1843, the Illinois General Assembly created a commission to designate a new county seat for Jackson County.