General Casualty has been part of a larger company since 1956, when its founders sold the company to Reliance Insurance Co. of Philadelphia.

William Roys started General Casualty in 1925, opening an office on the Capitol Square. The company 's first auto policy was written for a 1925 Model T Ford and a replica of that car is displayed in General Casualty 's Sun Prairie offices.

In 1942, the company built a 15,000-square-foot headquarters building at 117 E. Wilson St. Through its first half century, General Casualty 's stationery listed only initials rather than first names of its executives.

After additions to its building in 1957 and 1971, the company moved in 1982 to a new $9 million, glass-exterior building in Sun Prairie. Two more buildings, connected by heated walkways, were added later.

The Sun Prairie move didn 't come easily. Mayor Robert Schaben initially vetoed final approval of the project because he said it was too far from water and sewer lines.

When the company moved to its new building in 1982, it had 487 employees and $141 million in premium revenue. Today, the company has grown to 1,706 employees and $1.07 billion in premium revenue.

Some of the growth came during the late 1980s, when General Casualty expanded its commercial insurance business.

In 1990, the company was acquired by Winterthur Insurance Group of Switzerland, which later became part of Credit Suisse, a Swiss financial services company.

When General Casualty celebrated its 75th anniversary in 2000, the company wrote insurance in 12 states. Today, the company is in 25 states after acquiring Blue Ridge Insurance Co. in 2001 and Southern Guaranty Insurance Co. in 2003.

In 2004, General Casualty pulled out of Florida and decided to provide only commercial coverage in five other southern states, just in time to avoid the severe losses of Hurricane Katrina the following year.