Williamson County was formed from
Franklin County on February 28, 1839, and was named for
Williamson County,
Tennessee. Many of its settlers were from the Uplands South, traveling via the
Ohio River from Kentucky and Virginia. File:Williamson County Illinois 1839.png|Williamson County at the time of its creation in 1839 It became a center of coal mining, attracting numerous European immigrants in the late 19th and early 20th centuries. Labor tensions rose as workers sought to unionize and improve their wages and conditions. Mine owners resisted and several episodes of violence resulted during strikes and other work actions. Williamson County is often referred to as "Bloody Williamson," due to several outbreaks of violence that have few parallels in American history. These include the Bloody Vendetta (1876), armed confrontation between families and associates during the waning days of Reconstruction; the
Carterville Massacre (1899), a Coal Strike (1906), the
Herrin Massacre (1922), the Klan War (1924–1926), and the
Birger/
Shelton Gang War (1926). During the so-called Klan War, a mob of perhaps 1,300 men were deputized by the local sheriff. Starting on February 1, 1924, the posse began raiding the homes of local mine workers, mostly Italian immigrants. The Klan was inspired by both nativist and Prohibitionist fervor. Violence continued sporadically between bootleggers and the Klan. Twenty people were killed before peace was restored. In June 1915, a
Sicilian miner accused of the fatal shooting of a wealthy local resident was lynched in
Johnston City, Illinois by a mob. The Illinois National Guard was deployed to prevent rioting between the miner's supporters and opponents. They were also later ordered to various locations repeatedly during the 1920s to separate warring parties and attempt to keep order. The northwest section of the county suffered extensive damage during the
Tri-State Tornado of 1925. The county was also struck by two
tornadoes on May 29, 1982, which killed 10 people in the
Marion, Illinois tornado outbreak. On May 8, 2009, the cities of Carterville, Herrin, and Marion were severely damaged by the
May 2009 Southern Midwest derecho. ==Geography==