General Casualty was founded in 1925 in Madison, Wis., as a fire and auto insurer. The Company expanded into neighboring states in the 1940s and acquired several other insurance companies to fuel its growth. After outgrowing its downtown Madison location, General Casualty built a new office campus in 1982 on 140 acres in Sun Prairie, northeast of Madison. General Casualty expanded its operating territory to the Northeastern U.S. in April 2001 when it acquired Blue Ridge Insurance Company and to the South in November 2003 when it merged operations with Southern Guaranty Insurance Company.
In 2007, the Company was sold by Winterthur Insurance Group to the QBE Insurance Group, based in Australia. General Casualty and its sister company Unigard (Bellevue, Wash.) belong to the company's QBE the America's division, based in New York, and operate under QBE Regional Insurance, headquartered in Sun Prairie.